I'd like to see Deacon sing a song or two of his own at the concerts. I think it's been suggested before that maybe he could try to write with one or more of the other guys? He's got some good songwriters to learn from. If he doesn't seem to have much songwriting ability, it would be nice to see him sing a new song or two written by somebody else. Just MHO.
As to forgoing his life and living his father's, it's nice that people here make that conclusion about him. He obviously doesn't feel the same way. As you say, he's well compensated. Also, I'm sure he's learning a lot, and he's said that he finds it healing -- no small consideration when you've lost your dad at a fairly young age.