I think for right now it makes sense to have O'Quinn on the second unit, along with DWill, Grant and Galloway.
RLopez - he had 10pts in first qtr against Philly, so he's assertive when it's there for him. He got two quick fouls last night, one was a frustration foul after he missed an easy dunk attempt (Celtics probably fouled him, wasn't called, and he fouled back out of frustration)
I think RLopez will be fine and his offense will be there when it is needed. I think it makes a lot of sense to start KP alongside him - create more space inside with KP's range and mobility. Lance Thomas does not do that.
You left out Melo, who has looked very very good in pre-season. We may sort of expect it, but it's a good sign he's been so locked in on both ends.