1: yep that's pretty normal. Your just growing a little bit faster than the rest of the girls in your grade
2:Same here! i sweat alot too I even use clinical strength but I still sweat alot
3: You cant really do anything about it but so what just ignore them boys will be boys :/
this is all normal, you're just maturing faster than them. completely normal.
also, be happy you're in a bra. in a couple years, you'd be complaining if you didn't have to wear one and all your friends did.
for the sweating problem, it could just be going through puberty. or it could be hyperhidrosis. i'd recommend using certain dri, it works wonders. i use it myself because i feel like i sweat a little more than normal.