I love IT too, he's got a heart as big as the Grand Canyon. But the fact remains, he would make a great 6th man.
At 5-9 his defense is a liability, it's a destination spot for opposing teams to attack. When he's not feeling it with the ball in his hands, he gets terribly stubborn forcing his personal offense down the throat of the opposing teams defense, ignoring teammates while looking to get himself back on track. He does this to the point that Stevens eventually takes him out.
Another point is Thomas take a physical beating with his style of play. I've never seen a player hit the floor more that IT...sooner than later it will take its toll. I fear that years 29,30,31,32, will see a certain decline.
IMO Don't over pay him, his future should be as a star 6th man, where his wear and tear can be kept to a minimum, and his defense will be against 2nd line players.