I was trying to reverse pickpocket Caesar to get his armor, but I can't even pickpocket him! Even if it says "hidden" when I click "pickpocket Caesar" he just gets up and tries to kill me. Is this a bug?

have you tried using a stealth boy? if so, he's most likely "un-pick-pocketable". trying to give a key NPC like Caesar different armor so he takes off his own is most likely extremely difficult. did you check the wiki? it may say if it's even possible.

Well, the wiki says that his armor can be pickpocketed on the page for Caesar's Armor.

huh. probably is a bug, then. I don't know, probably the only way to get it would be killing him if he's going to jump up and attack before you can even access the pick-pocket menu, and obviously you don't want to do that....