Nope, as far as turn on or off, it's all the same to me, I'd certainly not say no because she asked me. Hell, many guys would probably even prefer, it all depends.
Fuck yeah it's a turn on. Unless the guy is a deuchebag, then he'd be happy to be asked out by a girl. I actually prefer to have women ask me out.
most of the time girls have somebody else ask me to talk to them, pretty gay, but as for the strong women......if andrea the giant had tits, id wink maybe (lol)