Above the very lowest leagues, most players are very polite. They are also very terse. Some common abbreviations are used in chat for a friendly (though fiercely competitive) match.
The following expressions are often used at the beginning of a match.
- gl: "Good Luck"
- hf: "Have Fun"
The following expressions are often used at the conclusion of a match.
- gg: "Good Game". This is the usual way to concede defeat.
Ok, so it sounds like you actually have two problems.
- How do you deal with the little things
- When do you expand
I'm going to address the second one first.
Don't expand if you're still dealing with harassment and large armies. Expanding is very much BW style play and largely is designed around the concept: Expand when I have Map Control. If you don't have Map Control and you try to expand, what's going to happen is that your opponent is going to shut you down with some small task force (like 12 Reapers or 8 Muta). You're going to respond with your whole army and he's going to pull away with little or no losses. So if you're losing expansions to harassment, chances are you just don't have the map control to expand.
Next you talk about how you're losing larger armies (40% to micro). Almost everything your army does requires 0 attention from you, except combat. If you're engaging in a situation where you will lose (split army) your response should be retreat to somewhere you can win. If this means sacrificing an expansion, sacrifice it. If you're walking into an unscouted position, retreat. Scouting is a far more valuable use of your time in these situations than micro is.
Now, if you're losing because your Zealots are in the back and your Stalkers aren't blinking, and you're running into storms, then the problem you're really having is how you macro. You should be building and organizing your units as part of your macro. If you're building your Zealots behind your Stalkers and leaving them there, that is bad macro.
Finally, if you are engaging a scouted opponent and thinking that you should win, then give over most of your attention to this battle. Perhaps build things via hot keys only, but don't move your screen for more than a second. Big battles require a lot of attention, and you should give it to them.
You also mentioned harassment in a couple of contexts so let me give you some good advice. Photon cannons are not designed to stop harassment, they're designed to delay it. It is far better that his Mutalisks spend the time to kill 2 photon cannons, than you build the 8 photon cannons to stop this raid. Use defensive structures as a delaying tactic.
Best Answer
There are a hundred possible answers to this question. As a rule of thumb you want Colossi first since you can get them a lot faster and you really, really need them against marines and marauders. Without any sort of AoE on your side, Terrans MMM can beat a Protoss army cost efficiently.
Once the opponent is building Vikings, slowly transition into High Templars which - depending on how many colossi you have left - either make his vikings useless because they can't really engage High Templars or they can cover your Colossi with Psi Storms against Vikings.
Alternatively, you can go for very fast High Templars and use a Zealot/Archon/HT composition though i wouldn't recommend it at your level. You really need to know how to engage when you use it, one bad engagement and you lose instantly since High Templars need forever to get energy for Psi Storm after they get warped in.
In general, i would recommend sticking to Robo units (Immortal/Colossi) as the backbone of your Warpgate army since High Templars can be really distracting from what you really should be doing, especially in the lower levels. You'll try to hit Psi Storms instead of macroing.