Re: Rondo's Cleveland series.
In a way, I think that series has become fools gold for Celtics fans on the order of Perkins' ability to defend Dwight Howard. The rationale for both instances is that since our young guy has accomplished this against a great player (or team), that means that our young guy will one day be able to do it against everyone. That's not necessarily true.
Rondo against Cleveland (and Perkins against Howard) fit very well into their strength/weakness skill set. Perkins has the size/strength to body up and defend against someone of similar size whose entire game is built on force...but he's weaker against guys much bigger (like Yao/Bogut, for example) or players that can go to the perimeter. He's limited. He's very good at what he does, and he's valuable for that, but he's not close to the best big-man defender in the NBA (which I sometimes see people saying, using his D on Howard as evidence).
Similarly, Rondo is quick and athletic enough to get into the paint/to the rim against any perimeter defender as long as the hand-check rules are being enforced. We know this, and have known it for 2 full seasons now. Cleveland had no one capable of defending the rim. Therefore, Rondo was able to torch them repeatedly. But on the flip side, if a team has dominant rim-defenders among their bigs then suddenly Rondo is human. We saw that against the Magic in '09 and '10, and again against the Lakers in '10.
For Rondo to be able to replicate his Cavs performance against a team with a dominant inside defense, he'd have to become dramatically better with his midrange-out game as well as becoming a much better free throw shooter. At which point he would become...Chris Paul.
Every player has good and bad matchups. I'm sure you'll find that Chris Paul does better against some teams than others. But Rondo's ability to get to the paint wasn't quite as bad as you (and others) make it out to be. You can see this on his nba hotspots chart, but while he struggled against Orlando in the 2009 playoffs (he made 44% of his layups/close shots), he made 57% of them this year. He took about 7 of these shots a game both seasons. So he's clearly improving in this area.
The 57% on 7 shots a game wasn't quite as impressive as the 61% on 9 shots a game vs the Cavs. But if you take out Rondo's shooting from the game he had to leave because of leg spasms his fg% on those shots against Orlando ould have been over 63%. He took a few more inside shots vs Cleveland, but I'd say that was because of Paul's offensive resurgence.
So I'd say that, in terms of getting to the rim and hitting his shots, Rondo did come close to duplicate his Cavs performance against a team with a dominant inside defense. The difference in Rondo's scoring in the Cavs and Magic series wasn't his ability to get to the rim, or his success in finishing at the rim. It was the number of shots that he took (since he was trying to be a distributor, not just a scorer). It's also worth pointing out that he hit 13-31 shots that weren't close to the rim vs the Cavs but 9 of 36 against the Magic, so he was able to largely duplicate his success against a better interior defense in spite of shooting *worse* from the outside against that team.