No, but there has to be an improvement in workrate. Hogan, in general, doesn't bring this to the table.
Few and far between. Warrior, yes. Slaughter at WM VII, you could maybe make a case for (although I'd argue they were about on the same level). Same with Bossman in the cage match -- although Bossman was approaching his peak at the time. Other than that, I can't think of anyone.
Probably. Hogan has a very basic moveset, and matches against other poor workers tend to be poor from a workrate standpoint (i.e. lots of resting). Hogan hides the fact that he's not a good worker with his impeccable timing and charisma. He's certainly not the worst worker I've ever seen, but he's nowhere near the upper echelon. Hell, Hogan would tell you himself that he's not a great worker.