As Gherian pointed out, a lot of 'personal' roleplay is left up to the individial doing the roleplaying. However, the example you gave of a bard doing a triple backflip onto a barstool is one I would argue with you on, since I can easily see it happening. Why? You might ask. Well, look at bard titles, Dancer, Juggler, Singer, etc etc etc. All of these point to some facet of bardly training...and if a bard chose to, 'roleplay-istically' speaking here, focus on one of those aspects for certain performances it makes sense. That being said, if you look at a lot of skills certain classes have there are certain other abilites that it is not so odd for them to have. A felar warrior being a gracful dancer, or a shaman being a good singer, or even a ranger being a good cook....all of these things could have a case made for them based on other skills within that classes/races repitoire.

That being said, I know exactly what you're talking about. There are a lot of Therans who are amazing in their multi-talentedness, and while I won't site it as a lack (or even poor) roleplaying...I think that they certainly don't stand out nearly as much as the people who, like you, chose to take a more 'realistic' stance in their roleplay and aren't jack-of-all trades. I think if you look at many characters who have stood out and been held up as paradigms of roleplayedly goodness you'll see that they were people who limited their character in some way. Since in a lot of ways, a rather amazing test of a character is to put a limit on him, and stick to it. If someone out there has never tried it, I suggest trying it, it's very interesting to place boundries and limits on yourself. A lot of times they'll piss you off and hinder you from doing something amazing, but on the other hand...just by having a roleplaying reason not to do something is often just as slick as having a roleplaying reason to do something.