I'd do Bradley, Smart, JJ, and 3 for Butler. Trade doesn't make sense if you move IT though. I'd happily add in Amir and Rozier and get Pau back as well.
so post-trade (return own free agents, no other free agents)
Starters
Thomas, Butler, Crowder, Sullinger, Gasol
Rotation
Turner, Olynyk, Hunter, Mickey, Zeller
Deep Bench
16, 23
DLeague/Trade fodder
Young, 31, 35
That is a much improved team that is one big free agent acquisition away from actual contention.