I don't see anything wrong with that set up, very nice indeed. I would put him up there for two to three days, see if he figures it out. If not, I am pretty sure he will by January. I would not worry about his feet or mites, just not an issue.
Mrs K
Truthfully - I would not worry about it. He looks very heathy to me. He has just not gotten everything figured out. I would expect him to just figure it out in the next 3 months on his own.
Maybe I am not seeing something - pictures of your coop and roosting set up would be good.
You could...