Rather than give my opinion on everything you said (since I have a lot of opinions on those things) I'll comment on the title and your two question marks.
John Bonham was the best drummer of all time by far.
On keyboards it's John Paul Jones imo with Ray Manzerak, Billy Preston and Jerry Lee Lewis as runner ups. If you include classical then they all take a drop though.
Bass: Who cares, they're bass players.