Re: RAF transfer
Very unlikely to have to do IOT or much if any officer training. I certainly know of (at least) one army captain who left work on a Friday as a captain and started on the monday as a flt lt - and not at the same location either.
He was an infanteer who became a rockape (RAF Regt) so I guess that was easier. Which illustrates the fact that it depends what you want to do in the RAF. If you know, then a good initial POC would be the appropriate JO desk officer at PMA at Innsworth - the RAF's MS equivalent.
You should be able to find out who you need from the RAF intranet sites, which, if you are serving, you should have access to. If not, ask a friendly crab...