However I have learnt that ineptly flirting is very bad and makes you worse than Hitler, incompetence is no excuse, etc. So I can't go out and practice dating skills.

No one said this.

If I do want to practice dating skills, that makes me a PUA

No it doesn't.

and worse than Hitler.

Being a PUA does not make you this.

But now I'm concealing sexual attraction, which comments on this post have established is definitely creepy.

There is a difference between not concealing sexual attraction and shouting it. But anyway, being creepy does not make you Hitler. It doesn't even make you a bad person. You are not morally obligated to make people comfortable in all circumstances. Making people uncomfortable for no reason is kind of a dick move. And making people uncomfortable is not going to lead to friends or girlfriends-- so if you have been specifically told that you are doing something creepy then it is a good idea to find out what it was and stop it. But that's it.

Seriously. I can see how the feminist rhetoric about creepiness overstates the issue, overgeneralizes and over-sensitizes some and I made those criticisms in this thread. But they're not nearly as dramatic about it as you're being. Have you ever talked to a woman about this who isn't preaching about it on the internet or enrolled as a women's studies major?

Edit:

Obviously now, having read about elevatorgate, I am less likely to try to flirt with women in elevators, but I would totally expect that I would do something equally as bad in a non-elevator-based situation. So, Hitler.

Flirting with women in elevators is totally fine. Asking them back to your room late at night, when you haven't met and have no chance is a little creepy. Neither make you Hitler (or any less hyperbolic bad thing).