First off, these things sometimes happen. If this is a one-off occurrence, I wouldn't be too concerned: people sometimes get it into their heads that they need to do something "weird" for no good reason. I was playing in an In Nomine game as an angel who could possess people/animals; I somehow decided that I needed a monkey, and we spent about as long planning a zoo heist (that never happened).
So, one-off: don't worry too much.
If this is a more common event, or if it looks like it might be (Tom sounds like he might encourage this kind of "weird strategy" thinking), there are a couple of things that have been helpful in my games:
talk to the "problem" player(s): remind them nicely (and privately) that there are other players who need to be included in the action and the planning. yes, this is the default answer to anything with the problem-players or problem-gm tags; it's the default answer for a reason.
remind the players that time is passing in-game. In this particular example, while Tom and Frank were discussing what to do with the interlopers, the captain could be struggling against his bonds, the captors could be rummaging around the cargo hold, a sailor could be whimpering behind a crate. As the planning session goes on, the captors might get more violent, roughing up a sailor who gets in their way. D&D does encourage some "free action" tactics talk among the players, but time does flow.
if they still don't get the hint, a brigand could actually accost the PCs: demanding money, ordering them around, etc.. Roll for initiative! And, remember that the brigands are totally getting a surprise round (are those still a thing in 5E? Sorry, my experience is almost all 3.5/PF). I'd encourage relaxing some of the rules about how long talking-type resolutions take (or, at least, suspend initiative if someone rolls well enough to warrant a brief cease-fire), but there comes a point where conflict is inevitable (this is a good thing: the whole point of RPGs is resolving conflict) and the PCs can't just talk amongst themselves any longer.
alternatively, poll the players to see if they want to continue with strategy or move into action. Tom and Frank can talk about tactics all they want, but if the cleric steps in to stop the pirates from harming their ship's captain, Tom and Frank will have to respond. This can backfire! Tom and Frank can be angered by the cleric acting "before they're ready"; therefore, I encourage mixing this in with #2: "Tom and Frank are whispering about what to do; Cleric: you see the brigands roughing up the sailor; Druid: they're dumping something unpleasant from the hold into the bay. What do you do?"
I'd personally be hesitant to actually use one, but I've seen suggestions to use a small hourglass (a 30-60 second timer) to let the players discuss how to respond to a new situation before in-game time resumes. The in-universe logic being that the PCs have been traveling together for long enough that they can quickly communicate how to respond to violence with a subtle gesture, where the players need to actually talk.
You'll have to be a little careful to not step on Tom's fun in planning intricate strategy, but that's relatively easy: make sure that there are plenty of encounters where the PCs know what's coming far enough ahead that they can talk for a few minutes in-game before the enemies know they're there.
What Surprise Means
Surprise is a judgement call on the DM's part that is situational.
The DM determines who might be surprised. If neither side tries to be stealthy, they automatically notice each other. Otherwise, the DM compares the Dexterity (Stealth) checks of anyone hiding with the passive Wisdom (Perception) score of each creature on the opposing side. Any character or monster that doesn't notice a threat is surprised at the start of the encounter.
Readied Action
Readied action uses the reaction for the same round that the action was readied. If every party member readies an action for the door to break down, and the door doesn't get broken down that round, the action is wasted. They can re-ready the same action the next turn. In that case, when the trigger happens, they all take their action (in initiative order (or [Dex] order) since they all have the same trigger) and the DM resolves them.
If a surprise round were to occur without the trigger being able to fire, the readied action is lost and the players will take normal actions on their next turn. I don't think that's how this should play out.
How I'd Rule
In the situation you describe, the players are alert because they are kicking down a door, so they expect something to be on the other side. They have even readied actions to take, so the ogres can't really get the jump on them -- the players aren't surprised.
The ogres would have been surprised if the party successfully beat the door down, but they failed the roll and the ogres heard the sound. They know that something is trying to come through the door -- the ogres are not surprised.
Readied actions will happen on triggers as usual (or not if trigger doesn't come, or if reaction is used to do something else like Opportunity Attack), as no one is surprised.
The three scenarios
RAW, there shouldn't have been a perception check. The players took no action that would give them one. That said, as a DM you can give them that extra heads up...
The Players' turns (and thus reactions) would be lost during the first round if the ogres surprised the players. Second round they'd act as normal. That is what surprise does. Otherwise, it is legal.
If everyone is surprised, no one can act for the first round. That's 6 seconds of everyone looking at each other in shock. No actions taken. Otherwise, it's legal.
It's legal.
Best Answer
As written, yes
The Player's Handbook outlines all of the details for creating characters. Nowhere does it say that personality traits, etc. are optional. D&D is meant to be a roleplaying game where you make your character act in accordance to that character's beliefs and personality.
That being said, all rules can be ignored by the DM if you so wish.
A character without personality traits will sometimes just be acting however the player would act. This can be disruptive as some players will make their characters do things that will get the party into a lot of trouble.
Or they might be fine; some players just stay quiet until combat starts.
The whole purpose of these traits is if you plan to build a story around the characters. A character whose flaw is greed might ignore the rest of the party while they are fighting for their lives in order to steal some valuable items. A character who has an insatiable thirst for knowledge might read a tome on a pedestal which is surrounded by long-dead bodies who have presumably done the same. A character who refuses to retreat when innocent lives are at risk might insist on staying and fighting an army of ogres approaching a village, even if the rest of the party want to run.
Keep in mind, though: for premade modules, this is less important unless you plan to adjust it to factor in your party members. There's no point worrying about a party member who has an alcohol addiction if they are stuck at the bottom of a dungeon with no booze.
As KorvinStarmast mentioned in the comments, the other use for character traits and roleplaying in general is for the optional rule regarding Inspiration. You might give player an inspiration to use if they do something particularly in character or for other reasons such as coming up with a clever solution to a problem.