Good questions. For me, I think we need to do the following:
If KG says he can't handle the banging all season at center and wants to go back to PF -
1. Sign a legit starter, a decent back up and then put Steamer or our young draftee at 3rd string - don't rely on him.
I'd target:
Hawes or Kaman / Aaron Gray / Steamer or Draftee
PF: KG / Bass / JJJ
If KG wants to play center, I'd get him a decent back up and spend more of my money at the PF position -
Center: KG / Aaron Gray / Draftee or Steamer
At PF, Target the following:
Illyasova, Humphries or Landry / Bass / JJJ
Something along those lines. I just wouldn't want to be in the position of depending on my rookies for major minutes in any scenario, regardless of how good they might seem coming in. If I'm presently suprised as with Kawai Leonard in SA, great - but I wouldn't bank it as my plan...