There has not been a single beat reporter mention a single word about Dez's 'antics'. In fact, all reports are that Dez has improved in the areas of being on time for meetings, etc. He still has a ways to go but all indications are that he is much better than last season.
I agree that he was being a bit of a drama queen, but I think that's a far cry from being a problem with his teammates. It's funny how sideline behavior is characterized based on the player. If Witten comes to the sidelines throws his helmet and yells, he's being a leader and most likely lauded and having as passion and leadership. Dez does it and he's problem.
The dude is immature, no question. But there's a pretty big gulf IMO from being immature and not knowing how channel that passion and being a bad guy. Dez is not a bad guy.