2. I have to agree with everyone else about Vader's No. It could have been done much better. The force crushing was fine, just the line stank.
(I will, however disagree with anyone concerning the Frankenstein tribute. I did think that was a nice touch.)
3. In the last Clone Wars season 1 episode, Grevious took on 4 (or was it more) Jedi at once using 2 arms (not 4) and a leg, and defeated several of them.
Obi-wan beat him alone and with Grevious using all 4 arms.
In other words, Grevious wasn't tough enough. He did some impressive things, just not enough of them.