Matt, I am ready and willing to debate you about the whole "dork" thing, partly because your examples are incoherent, but mostly because you end up sounding like a jerk about that.
The worst part is, I get what you mean about the person who has a specific idea about what's the right way to have fun or to do something and how annoying that can be when you don't share that idea. A dumb, but clear (hypothetical) example:
It's boardgame night at the Besser-Schneider household and you two are playing Scrabble. You just want to spend time with your wife, while she wants to play Scrabble seriously. You're just joking around, not taking the game seriously--but she really wants to play the game and makes sure that you're playing according to the official Scrabble rules.
In that scenario, she's a dork, which is a bad thing to be. But also, in that scenario, you're also being kind of a jerk. I'm not entirely sure what to call you here--a flake? The point is, you are both ruining each other's nights because you have different and inflexible ideas of what boardgame night is about.
So, yes, being a dork is bad, but so is being a flake. You're both equally at fault here, right?
Now take this (hypothetical) scenario: a bunch of people come over for boardgame night, but it's really just an excuse to hang out with some friends that you don't get to see too often. But Danielle still really wants to play according to the rules. And so she keeps badgering people to play in her dorkish way, which kind of ruins the mood for everyone there.
In this scenario, you all had a clear idea of what would be fun--hanging out with each other--but one dork just wouldn't let people alone. In that scenario, it's clear that the one dork is making everyone else's life a little less pleasant.
We could flip that around: everyone came over to play seriously, but one person insists on getting drunk and having their own kind of fun. That person's the asshole, right? Do we agree so far?
When a group of people get together for a reason, someone who intentionally comes over to do the opposite is kind of an asshole.
Now let's get to your examples:
1) Bringing keyboards to a drum circle: it could be a funny sketch--but everyone else in the group agreed about what they were doing there. The guy with the keyboard isn't some brave protester speaking truth to power. He's just being kind of a dick.
2) Getting high at a wedding: The guy who pissily says "come on guys" is a dork since, as you said, you're being discreet and not really getting in any one's way. We're agreed on that. But if you were to light up in the middle of the wedding ceremony, that would be you being an asshole. I mean, you're at a wedding, so I assume you're wearing a suit or dressed somewhat nicely? Because we all kind of agree that there's a way to behave. By going to the wedding, you've sort of already agreed to the rules of the wedding. [Note: edited this example slightly for clarity.]
3) Going to the library during the big game: And here's where I think you're being really kind of a hypocrite unintentionally: when you say "go to the fucking game... show your spirit" you sound like a big old dork. Because you're saying "there's a right way to have fun on game day." You're telling people that your idea of the way to behave is the right way.
Now wait, before you try to accuse me of hypocrisy, here's where I would agree with you: if someone went to the game and played distracting music--or even sat in a very visible spot reading Proust--that person would kind of be a jerk. Because everyone else came to the game to have a good time; so going to the game to conspicuously not have a good time is bringing a keyboard to a drum circle.
You might argue that going to the library is a form of visible protest, so it is kind of like bringing a keyboard to a drum circle--except, of course, you can see how it's not. I mean, if you agree to go to a drum circle or a wedding, you agree to a set of social norms and behaviors for a little while. And if you go to the big game, you also agree to that set of social norms. But there are bigger, multi-headed institutions where agreeing to one aspect doesn't mean agreeing to all. If you go to college, you're not signing on to everything about that college, anymore than you moving to Texas means signing on to everything about Texas.
(I'm especially concerned about this point because I'm an atheist living in Texas, in a small city with a lot of churches. But just because I moved to a very Christian city doesn't mean I've suddenly signed on to all of that. Similarly, if you go to a big sports school, it doesn't mean you have to love sports.)
4) The secret show and people feeling ripped off: I don't blame you--yes, when someone asked if you wanted to do the "secret show" and you weren't sure what they meant, you could've asked; but also, the organizers could have told you. This would seem to be one of those cases where some communication about what was expected could've solved the problem (much like hypothetical boardgame night could be saved if you and Danielle talked about what you wanted from it).
But that doesn't mean that the audience-members who were upset didn't have a right to be upset--depending on how the show was advertised. I mean, if I hear the UCB is going to be performing and I get to the theater and you guys are putting on interpretive dance, I'm going to feel a little misled, just as if I had gone to see the Cubs and they were doing improv. This doesn't really have to do with dorks vs. flakes directly, though you can see how it revolves around some of the same issues of expectation and communication.
Like I said, I'm ready to argue with you about this on air sometime, though really it would just be me reading you this long comment.
In conclusion, when is boardgame night at your house and what game should I bring? Because I really don't want to be here in Texas much longer.