I think 1 Regt disappear as part of the Wildact upgrade
I'm not so sure on that one - it will the Wildcat Force - or whatever name they come up with for it. In the same way that 3 and 4 Regts still exist within the AH Force and the way that the individual SH types are now considered as Forces i.e. Merlin Force, Puma Force, Chinook Force. The move to Yeovilton is as much administrative / engineering and cost driven rather than by any desire to remove Regt number plates.
Leon - Ben / Odi Stn Cdrs report direct to JHC for TORs, OJARs etc. As has been described already, think of JHC as being loaned the assets (stns, ac and personnel) by the respective single services. It's a bit like children at school - no comparisons of JHC to a creche please (far too obvious!). The parents 'own' the children and have ultimate responsibility for them. However each day then take them to school and hand them over to a teacher who is responsible for what they get up to during the day, discipline etc. As 'owners' the parents have an input and ultimate sanction, but in practice let the school get on with things unless it all starts going horribly wrong.