What kind of audience do you want, the people coming for your wardrobe or music?
You sound like a "I earn 25 million dollar a year-rockstar", I seriously couldn't care less about what the audience thinks of my t-shirt.
Do not agree with the dancing and people seeing through it as well. Our chiptunes are not for live purposes per se, yet the basslines and drums sound pretty good on a big PA, if you give a proper example and show people you're enjoying yourself, people will join that vibe faster.
I'm sorry if you misunderstood me because to me, you've agreed in full as long as you understand that giving the music more importance than your presence at the venue is okay.
I said "your clothes are your costume" partly because that's a paraphrase of what my mentor from the proverbial day taught me, my background is in the pretentious jazz/rock stuff that went away in the 70s for a reason. (Teacher was one of those folk/pop acoustic guitar types.) The intent of the statement is, you should "look like" your music.
It does depend on what the intentions of your music and performance are. To me, a live performance is specifically a way for people who could listen to your music anytime through recordings can say, "I got to see/meet xxxxxxx." You don't even need to play your music to accomplish this, but once the meeting is over, I'd think you want the people who meet you to think, "that guy is cool," as opposed to Telerophon's experience of "What a jerk."
Downstate makes the best point of all though, unless you're planning to go on "got talent" or "idol" it's not like this is serious life changing stuff... Or is it? If you're not trying to market yourself and you don't like performing, then... don't. It's okay.