Not a rock but work at 'Rock HQ' in the depths of suffolk, so if you need details send me a PM and I may be able to help and even point you to some of the right people on the RRPT etc (Regt Recruiting Team)
A few easy open source answers are given here:
1. RAF Force Protection is divided into 6 FP Wings around the country with the Stn Cdr at Rock HQ acting as the 'Force Cdr'
They are controlled thru Strike Cmd at CHQ, High Wycombe.(inc the Jt CBRN Regt also based at secret Suffolk HQ!)
2. Trade Trg is too vast to explain here needless to say, they are a very professional bunch who are highly respected by the likes of the Secret Squirrels!

3. Head of RAF FP is an Air Cdre (1star) who is also head of the police. Usually an ex-Stn Cdr at Honington in later career.
4. Not sure if they go higher than 1 Star. Well respected by forces all over the world and although given 'stick' all thru the RAF, are highly respected by aircrew et al for the vital role they perform in defending the Ground Defence Area (footprint around an airfield)
Any other Q's send me a PM
PS I always tell them in the Mess that the RAF Regt is full of people who were too scared to join the army and ended up in the RAF's infantry. Goes down a treat