For me this is largely about expectations, signposting and player agency.
The first point is expectations. How much was the tone of the campaign discussed before you started? Did you make sure the players were aware you were going for a world where their actions can have negative consequences and that you would follow through on these? This might sound silly, as I'm sure for a lot of people what I've just described is where the fun of roleplaying is, but you'd be suprised how many players have the expectation that they are never going to fail.
Then there are signposting, opportunies to spot the bad stuff and if it happens then do something about it. If I were a player and the only warning I got that something really bad was going to happen was right at the beginning of an adventure 3 months ago, then I think I would be entitled to be a bit frustrated. People have short memories and cannot be expected to be able to identify the important bits of information in everything you tell them as GM, let alone remember it for weeks/months at a time.
Lets take your first point as an example. Have they been made aware that the Kobolds renege on deals and have a reputation for not giving gold? When was this and by whom? Was it someone they had a reason to trust? If their only warning was a brief encounter with a minor NPC 10 weeks ago then you might want to think about reinforcing this somehow.
Assuming that you've given them plenty of warning and they still end up with no gold, the most important thing is to ensure that you provide a way of getting revenge and/or recompense. I know if I'd been doing a load of dangerous work and didn't get the gold I was promised that I would want to do something about it. The most important thing here is to give players the opportunity to act in revenge/response to whatever has happened to them. Maintaining player agency when something bad has happened to their characters is key in ensuring they don't feel hard done by or upset. There is nothing quite so bad as effectively being told 'Haha! You don't get any of the money you were promised and there's nothing you can do about it!'
Well that sounds about par for the course. I have a regular group that I DM for since 2009, and your player archetypes sound pretty familiar to me. (And yes, those are the real archetypes, not what is described in the DMG).
Don't worry so much
First off, don't worry so much. From your post, it seems like it's going ok. The important part is that you have fun. If the group has fun, there's not a big problem, even if you as a DM might feel you are doing stuff wrong.
Talk about it
After a session, or maybe during a coffee or smoke break, ask the players about these topics. What do they like, what do they dislike? How do they think the game can be improved?
If everyone says it's fine, great. If not, I am sure they have some suggestions for improvement. I do this after every session, sometimes for 3 minutes, sometimes we discuss this for half an hour or more. It really helps.
Play to the player's strengths
If a player or his character is good at something (and everyone has has a speciality), give him or her a chance to use this strength. So the rogue player is inventive - give him a chance to use his wits. What I do is that I generally prepare some specific additional puzzles or challenges for them. I think the best way to integrate those is if you have a fight and at the same time some additional pressing matter that people have to attend to, either with some skill checks or just with good ideas. So maybe while the party deals with the brunt of the attackers, someone must slip through the enemy ranks and disable the ballista before the city walls are down.
Help your players
So the ranger treats this like a video game, but is not pro-active enough. Well, he doesn't have to go shopping. Drop some loot for him that is a part (one third) of a magic bow. Maybe a bow string made out of dryad hair? This should awaken his video gamey instinct to collect all parts, involve him more into the story and finally lead to him getting a better bow.
Some answers on this board stress how important player agency and pro-active players are for the game. I am not sure I fully agree with this. Some people are just naturally more passive, and if you can help them so they have more fun and everyone has more fun, just do it.
Use mechanics to cover the player's weaknesses
For the wizard - maybe propose Sense Motive, Gather Information or similar (Insight in 5e) checks when you feel he's missing something. If he succeeds the check, give him a hint. Like this, you can use the character's strength to cover the player's weaknesses. And after a few successes, it is likely that the positive reinforcement will lead to the player doing this on his own more often.
A similar thing about this assertiveness: Have a friendly NPC cast a spell him, or maybe an enemy a curse, and tell him how this makes him feel more assertive, mighty and filled to the brim with power. Sometimes this helps such players to slip into a role they would not otherwise take on.
On the other hand, specifically this is not really a problem in my eyes - a nerdy shy wizard doesn't seem so out of place.
Offer help with their characters
So this is a two-sided sword. It might be a great help, but can also ruin a lot. Make sure the players want and appreciate your help with their characters before doing anything. You really want to avoid messing with 'their guy' if they don't want you to. But if done right, it can be a great help to certain players.
One of my players is like your barbarian player. Doesn't like to read the rules, but is very enthusiastic and a great addition to the game. Before a new campaign, I generally have a skype conf with him and discuss the background a bit and what character he wants to play. Then I build a character for him, send it to him and we discuss some changes he usually wants. Once we have a character he's happy with, I make him a nice colourful character sheet in Numbers with all the important stuff up front. This worked out very well. It allows him to focus on the game, and not worry about details or picking whatever CharOp stuff from way too many sources he's not interested in, while still playing his concept and being on a similar power level as other players who are more into optimising.
Allow them to rebuild or change characters (within reason)
Sometimes, a new player might choose a character that doesn't really fit his play style. Might be the wizard player would be happier with a sorcerer - new players tend to fare better with the simpler approach of having a few known spells instead of building a spellbook and preparing their daily prepared lists.
The system
Finally, maybe D&D 3.5e is not the ideal system for players who don't read up on the rules themselves. If your group is open to change the system, I can suggest two options:
D&D 5e. While similar in many respects, it has one advantage: A lot of stuff is just way simpler and easier than 3.5. While 3.5e is my personal favourite among all D&D editions, for my main group, I have switched to 5e, and we haven't looked back.
Games with far less rules: Dungeon World or Fate come to mind. I have played them, and had fun, but for my group, it was not the right choice. We like the miniature battles and everything around that. But those are certainly great games.
And, in the end, the evil master plan
Of course, all this cuddling and making players happy only serves one goal: to make them experienced enough so you can start being a true evil dungeon master. Once they know the system, know their characters and have a fair chance to survive bad things, the fun starts: Poison, traps and and horrible dismemberment. It's no fun punishing them if they have no chance to deal with it. But once they have shown they are up for the task, you can start driving the finger screws in, and let them into the tomb of horrors.
Best Answer
(This is advice for games that are played in person or in a largely synchronous setting like a chat. If you're playing by forum a lot of it won't work well just from your end, and you'll need to establish an alternate gameflow by sharing your players' concerns with each other up front.)
The hot-headed fight-happy freebooter who has to be restrained by the better angels among their companions is a reasonable character to want to play, and you can make it work, but not accidentally. It's possible for characters in Dungeon World to meaningfully clash with each other without running into the issues that might arise in a game with a more rigid action structure.
I'll say this up front: it's only going to work if both sides are okay with letting the dice settle this, and that means being okay with every possible outcome, as long as they get their chance. If Leafwillow and Sir Justice's players are cool with trying and failing to hold Grognak back sometimes, and Grognak's player is cool with trying and failing to get out from under Leafwillow (who is currently a hippopotamus with a wooden leg) sometimes, then everything's cool.
So here's how to make that happen. Well, first:
0) Nothing Happens Unless You Let It
Dungeon World is a conversation. When you're having a conversation about where to get dinner and somebody shouts "Jack in the Box!" you don't all just immediately go to Jack in the Box because it's the first thing somebody said, do you? You let everyone talk about where they want to go and make a decision together after hearing what everybody has to say.
In much the same way, when you're describing a tavern scene and mention a cloaked figure, and Grognak's player screams "GROGNAK SMASH!" and pitches some dice, that doesn't actually mean that Leafwillow and Sir Justice have to stand there poleaxed while Grognak smashes through three poker games and a marriage proposal to get at the cloaked figure. You're the GM. You control the universe. Nothing is going to happen until you say it does, and that means that you can take Grognak's input without saying what comes of it, and then turn to Leafwillow and Sir Justice and let them have their say.
Okay, they've all had a chance to tell you what they're doing in this open-ended scene. Now what?
1) How To Stop A Fight
Dungeon World has no concept of initiative order or equal goes. People take actions and get the opportunity to take actions as it is dramatically appropriate.
So, when Sir Justice stands in defense of the tavern patrons and rolls Defend, and when Leafwillow frantically grabs at Grognak to hold him back and rolls Interfere, this doesn't "use up their actions". It's not "Grognak's turn" again. You get to decide how the tavern reacts and who gets the spotlight as a result of it. "I'm going to let go" could turn out to be excellent leverage for Leafwillow to Parley with the cloaked figure, for example.
This second bit is the more usual flow of running Dungeon World, by the way. Everyone entangled in a dramatic situation, and you pick one person at a time to talk to and make some progress on their corner of it. For those times when you're just describing the world and not necessarily looking at anyone for an answer, you're not obligated to humor the first person to speak up - you weren't talking to anybody, so you can wait to hear from everybody.
2) A Little More Conversation
But you also mentioned wanting their characters to talk to each other more, which is also cool. So here are some ideas for letting that come out.
If people are okay with playing off each other dramatically, okay with not succeeding at their violence/nonviolence as long as they've had their go, then having some of your adventuring group butt heads now and again can make for some really satisfying drama. Just be ready and willing for either side to come out on top.