Maybe he did some questionable things, but after everything he went through, he wasn't a kid anymore. Yes, he was mature for his age before all the bad things happened, but his way of thinking had changed after those experience. You can clearly see how much his tone and approach has changed, when you compare some of his books prior and after his father's death.
He hired the actor because he didn't want to hurt Bruce's feelings. The guy just wanted to adopt him and Tim didn't know how he could refuse such a generous offer. But Bruce was actually proud of him. They are both twisted in so many ways.