I think that Minny pick comes online as soon as the draft ends. , it's possible that GS trades down with ATL or Detroit and then tries offering that lower pick and the Minny pick. We'll see.
I don't know that Harden is going to the Nets. Unlike with Westbrook, I think teams in the upper lottery will be willing to fork over tons of value for him. I'm not sure Houston will prioritize making Harden happy if the result is a way worse deal. I wouldn't be surprised to see the Warriors come away with him.
DeRozan actually does make sense for them for the same reason Hayward might. Did he opt out? If so, they could just lose him in free agency. If not, then I don't know that there's a trade between the teams. Does ATL want to drop all the way to 14? Would Ainge even be willing to give up 14 in this deal? DeRozan being cheaper works in SA's favor, though they'll have to be willing to miss out on some extra value to make sure they get a deal done before the trade capital dries up.