Let's face it, Bull never was a 'good' Qunari. Oh, he may talk all good and how Thedas would be better under the Qun, but deep down inside he knows that it would take away the good that he does like about those outside of it. He may hate magic (or at least weary of it, which makes sense being how he had to deal with the 'vints'), but doesn't agree with the treatment of the Saarebas (also read that little children's story online from leaks. Qunari are dicks). He says the Qun is a good life for a lot of people, but admits that it isn't the same for many others. He says that Thedas would be much better if the Qunari took over, but knows that the war to do that would spill a lot of blood plus a good share of people would most likely become mindless husk if they don't sumit (which may be a good share of Thedas when you think about it).
Bull is too open-minded and knows for all the good it does, The Qun is just as bad; if not worst in areas. Even if he sticks with it, it'll likely kill him just for the stress that he was caused back in Shearon. We talked about that tons of times already so no need to touch on it again. When his Tamassran was glad he 'got away', you know that him becoming Tal-Vashoth is the best outcome for his personal mission.
Yeah, he's still afraid that he'll become those who fought in the past; but at the time the game ends, he comes to terms with it and makes the best of what the future may bring. He finally can say 'life is good.' Sure the fear still linger; Bull has a 'family' that cares for him, just only not by name. And the many friends he made within the Inquisition plus his relationship with the Inquisitor or Dorian.
Trust me when I say he'll be okay.
Also, can someone show me the Chargers bit in WoT? Don't know if I read that one yet.