Well it work this way:
Your current AF of X (no matter how high it is) is incrased by base AF Buffs up to a limit of 6 x 50 if caster or 6 x 51 if caster rr5+ pr 6 x 100 if non caster or 6 x 101 if non caster rr5+ - your gear ofc means if you have 606 af from gear as pala the buff does nothing with buff bonus on gear but you can cap af even with lower buffs. Spec af is allways added no matter what you wear. And the Af Bonus on Gear is bonus % of your Base Af added on Top. So the answer is: A naked character is affected by every kind of af buff and the buffs are even affected by buff bonus but af bonus on a naked character do nothing.
But ofc you still buff base Af even if it do nothing to you becouse of buff removing ML style.
I think that they do , and will be affected by player level ..
That is also true, every kind of Buff is dampen by Playerlevel it is targeting. #Buffcap