I don't think Shumpert would've fallen into the second round. I don't see an excellent defender and monster athlete like Shumpert falling into the second round when defense is at such a premium nowadays.
I do think that Shumpert was picked because he'd actually get minutes in NY as opposed to Singleton and Faried who probably would've played 6 minutes a game off the bench at best.
In any case I think he's good to have if we dump Fields or Douglas in a trade for CP3 and/or D12 (I've given up on Deron even though we all know Mike D has a huge hardon for Deron, plus CP3 is better).
With Nash? I think we could sign Nash as a free agent. I think Nash would take the minimum or close to it in order to win a title and play near his home (he lives in NY in the off-season), and with the money we save by getting Nash instead of going after a superstar we could pick up a good defensive center since those guys do not come cheap.
PG - Nash
SG - Shumpert
SF - Carmelo
PF - Amar'e
C - (say someone of Dalembert's caliber).
That's a pretty damned awesome starting 5.