does anyone know if the dependent of L1 can go to school? work?

yea,

L2 i.e L1 dependent visa can work and study

 

for more detail see

http://www.immspec.com/l2-visa.htm

sampada

So after being in L2, if i decide to go to school, do i again have a F1 status?
Do you know how L1/L2 can apply for green card?

No you dont have to chang eyour status as long as you want to stay in that status. You have to be in F1 to get OPT or CPT that may be the problem. but since L2 can work dont know how you take this.

I dont know about the green card.. hey why dont you google rather than asking here !