Which is why I said medium term. They were still the Junior partner in Harrier as well.
The problem comes with a ‘potential handover’ is that still leaves you significantly short of number of professionals that are in the essential, but out of sight, jobs such as capability/requirement jobs, engineering/airworthiness/capability assurance jobs, development/trials/tactics jobs, and lastly headquarters, etc.
As you said none of this is insurmountable however the RN are providing (something like) 40% of the front line staffing, which of 3 Squadrons (4 if you count 17Sqn in the US) is going to leave them short around two-three hundred trained people. Note this is just at a squadron level, not counting staff and HQ jobs).
The RN is not structured, and couldn’t be for a significant time, to run F-35 by themselves.