Although I'm not necessarily opposed trading away Rondo I'd say that return is relatively underwhelming.
In the instance that Rondo would be traded to Houston, I think it would be rather safe to say that they at the very least would enter the playoffs in the west. Considering the disparage between the conferences, a conservative estimate would be to say that both picks would be past the first 18 selections in the draft. Granted, draft position and eventual talent often diverge (Rondo as a 21st pick is here an excellent case), but I would assume that lottery picks for Rondo would at the very least be possible.
Furthermore, while Motiejunas is definitely an interesting prospect, I am yet to be convinced that he at any point can become a starter in the league. From my perspective his talents are better fit to be a roleplayer that can switch up a teams offensive strategy (i.e. swapping a non-shooting big-man with a shooter). Simply put: he is not a starting center currently, and has not shown anything thus far to be on that path.
Regarding the NY trade I'm also rather sceptic - Shumpert might be a good defensive player, but we've already got an undersized, terrific defender who's not really a 1 or 2 named Avery Bradley, who just got paid this summer. Why do we need a slightly-less pesky and overhyped backup? As Fafnir notes JR Smith is by himself negative value - and not particularly young, talented (or seemingly motivated) to perform up to his past (unreliable) standards.
I like the Green dump, but would hope that Bass could net a pick himself, not because we need them, but rather because a 2nd rounder is hardly a better asset than he is. I don't think he's needed in Boston as of now, but I think he could have significant value to other teams.