In making the case for Troy to go to heaven, I think that one would have to point out his sense of financial duty and responsibility as a part of his being. Troy recognizes the obligations he has to his family and his children. He does not evade them. This should constitute as some level of good that he has done. When so many knowingly abandon, Troy refuses to let go of what he knows he must do.
At the same time, Troy does his best to be the best father he can. His own experience is one of abuse and blight. Yet, he seeks to impart the best wisdom he can to Cory. Troy seeks to overcome the pain caused to him in the past. He tries to transcend it and not victimize others the same way he was victimized. The primary fault that one can lay at Troy's feet is that he was emotionally unavailable. I think that Wilson's characterization of Troy is one that shows such an intimacy is different when so much social and personal abuse is heaped upon an individual. Troy does his part to try to overcome this in being as best of a father as he can to his children. This has to be credited in his "account" in analyzing whether or not he is worthy of heavenly ascent.
I would also suggest that Troy's sins are the result of unintentional cruelty. There is little to indicate that Troy deliberately hurt someone or intended to cause someone pain. Troy was never sadistic, enjoying pain caused to others. His transgressions are results of the heart- unintentional acts. If the standard of heavenly ascent is to condemn unintentional cruelty, then I think that heaven becomes a very sparse place. It is here in which I think that one could make the case that Troy is worthy of going to heaven.