1. Yes. Doing things which are against the social norm makes you feel stronger, makes you more aware of what is possible. In fact I would advise deliberately breaking social boundaries, doing shit like push-ups in public or going for a kiss in the first ten seconds, just so you know what it's like to be seen as a complete loser. It's not the end of the world. Once you have this unreactive quality, girls realise the different energy, the capability to be yourself and not give a fuck about what any douchebag at a club thinks (they're all insecure anyway). Someone I met once said they meditated in clubs. Why not? Who cares what anyone thinks, you hardly know them anyway. When you're 17, the social heirarchy is king. In Uni, that doesn't matter. At all. So ignore it, man, and the ladies will notice.
2. Of course you could have. The important thing is not to get hung up on whether you made mistakes, because that cements you into some expectation of how you're meant to behave, and that stops you from learning (social heirarchy is a bitch, man). So by all means, look at what you did and how she reacted, and learn from that. In this case it looks like she's interested, so hopefully you'll get in
good luck