Yeah, I get Barnes' desire to play small ball at that point in the game to shake things up and make something happen, but as soon as it was clear that SC was going to take advantage of that size mismatch, Aidoo needed to be put in the game.
I thought that Barnes panicked a bit in the second half and went away from the ball movement and P&R actions that were working well early except for the inexplicable amount of missed open layups, and settled for DK iso's and the long contested shots, with everyone else standing around. The UT offense resembled the worst of previous years' offenses in the second half except for DK's heroics. I'd have preferred he stuck to the ball movement offense, figuring the easy looks would start to drop.
As you said, two things that have been issues even in recent wins have been the erratic FT shooting and awful defensive rebounding, both of which affect energy and moral, as anyone who has played the game knows. There aren't many things worse than a great defensive stop ruined by giving up an easy second chance bucket. Those will eventually take their toll, and they did.