1. Honestly, I think Wilbur created l'manburg for a sense of stability. He could control what's going on, so he didn't have to worry about something going wrong ( even though it definitely did go wrong ). 2&3.To me he gives off bpd symptoms, so the betrayal from Eret, was probably the cause. This is also why he would see dream as his hero. 4.I think he would be splitting dream, he rescued him even though they were enemies for a long time, so that would give him the impression that this dream is the "hero".
2. I think he sees Tommy as something he will lose easily, and can't lose. He doesn't exactly see him as a possession, but someone that would betray him, just as he saw others do.

I'm happy if you try to debate my answers, I get hyperfixed on ideas so often I need that push! Hope you are doing well and staying safe btw