None of us can predict the future so I will acknowledge up front this is just my opinion.
I don't think the Raps stand a chance in hell of getting Westbrook.
1- OKC management loves him. Woj has mentioned this more than once in his artcles. It will take a great package or an amazing player to pry him away.
2- Westbrook is exciting enough that several teams will want him. OKC will get multiple offers and at least one will be better than what Toronto could offer. If forced to, I could think of a couple of hypothetical offers other teams could make.
As for Rondo, that makes more sense to me. I can see that happen, since Boston could be rebuilding soon. And, as has been reported, Boston has already tried to deal him when they were still looking to contend. Ainge is willing to shop him.
In my opinion, it would depend on what Boston does with Pierce. Does he retire as a Celtic? Pierce still has some game. If Pierce stays, then Boston is not really rebuilding so much as they are "reloading". Once Allen and KG expire this summer, Boston could use their cap space to add a couple of good pieces next to Pierce and Rondo and they would be back into the top 4 in the East. If Pierce gets traded, though, I could see Rondo being traded for a package the Raps could offer.
I don't see Rondo as a top 3 or 4 PG like some here do, but he has a respectable contract and is still a solid PG. I would be happy to have him, especially if the pick is outside the top 3.