I think it's weiiiiiirrrrrddd. But if she was really sexy then sure. lol. Also, if she was a really nice person, but people who would have purple hair aren't really my type I don't think, but you never know. I'm sure there are SOME guys who won't mind. :) If they still do, don't dye it purple ;)
Depends on the guy... just don't try to go all... "cos play anime girl" cause then you may want to seek medical attention. Either that or save it for the foreplay. But I've seen some girls with some interesting colors and still look very cute.
I dyed mine bright red, dark purple, black, and now hot pink. Mostly, I just get hit on by guys who are more my type. If you like more straight edge frat douche bags, then don't do crazy colors. I think purple hair rocks, though.