Bob Hope was the answer to the first. You had the other two right (Blessed played the Duke of Oxford, IIRC). The movie came out in 1989, I think; I wrote "relatively recent" because there hasn't been a more recent filmed version of that play that I know of.
DQ:
Last name start with B?
IQs:
Did a cartoonist show you with a hat that was much too big for you?
Did you once play a character who hid a fugitive while doing the dishes?
Did Chief Justice Rehnquist quote a poem about you in a case about flag desecration?