Need this Cleared up! Thanks blues :D

Over the past 2-3 days i've been hearing alot of this and that, with no sound proof...so i've got afew questions that I would like yes/no answers(explain if needed by all means :D

1) Do i need a facebook to play starcraft/wow/diablo3?

2) say i have facebook... do i have a choice to keep this private from my battle.net?

3)what benifits do i get from having them "bound together" ?