Cun and Metu for Johnson works salary-wise. I'm interested if folks balk at including Chim, especially if those same folks keep pushing for including the Toronto first in deals. Swapping out Metu for Pon and a second probably also works, but Detroit would probably value a Spurs big more than anything else they could give. It would not surprise me if Pop legit thinks Dante is a better player than Stan though, and wouldn't do that deal.
Something like Pau and the Toronto first for Temple and Green could work. But I don't see any reason to value the savings from Gasol's deal worth the price, and they don't really have anything in the middle to make up the difference. That pick is going to have legit draft value, I think. The team is winning themselves just out of range where a very good prospect HAS to fall to them, so having the mobility to hop up a few spots could make a huge difference in getting their forward of the future. Even if they stay put, it looks like some good players should still be around when they get to the bottom of the first. It's worth way more than role-players and cap savings in a year where the team is likely over the line anyway.
Thompson is okay player if you mean in the context of a guy to compete with Poeltl for minutes behind Aldridge. He's not a well-rounded guy though, and definitely not the mobile defender to fill out the starting unit. I wouldn't consider trading Pau for him a win for SA unless they got value out of the deal on top of Thompson. I really don't see Burks as that value, btb. He makes too much and doesn't really provide something the team is lacking. Either the Cavs have to give up prospects or a pick or they'll have to take back a contract like Mills to give SA financial incentive to do this deal. I personally would consider something around Thompson and Clarkson for Mills and Gasol, since it's salary-neutral and gives the Spurs extra money when they might really need it. But it's probably not what the Cavs are looking for.