He's not good enough to be a number 10, though. Or at least not good enough to be a very good one. You talk of Rooney needing service, and being provided with plenty of good balls, in order for him to deliver.
Isn't that part of the job of a number 10, though? At his best in that role, Rooney was capable of dropping into midfield, putting pressure on opposition midfielders, and linking up attack and midfield fantastically at times. I don't see how the current Rooney will be able to do that: he's slow, lethargic, and while he's still capable with a ball at his best, I'm not sure he's anymore capable than, say, Martial or Ibrahimovic will be; players who will probably offer us much more overall.
The problem with this argument is that for all your belief in Rooney, you say he needs to be accommodated for much more than a player of his supposed ability should be. And I'm not even sure he'll play as a number 10, either. Mourinho made it clear his role will be up front, and it's possible that will be as a main striker.