To answer your original question I would say no it is not but that some level of confidence is a turn-on Good luck If someone is interested it doesn't really matter if a person is shy or quiet IMO.I would be a quiet guy in real life myself and if someone isn't interested just because of that then I'm not going to try and change my personality just to suit them.
Likewise, a woman may appear aloof or disinterested, when really her shyness prevents her responding as she would like.
As for the nights out situation I know how you feel!
You gotta switch from worrying about what the women think of you and just focus on your own good time with your mates, don't care as much, see what your friends do and try pick up a few things.
I meanwhile am the one that stands in the background looking on..
Needless to say I don't have the best of "luck" so to speak...