"What control over CH Scout pack did CH School/foundation have ?"
I may be able to help a little bit, but need to explain my involvement. I was never a member of the Scouts, but became peripherally involved over Barclay Hankin's Will. In brief, he was an Old Blue and somewhat eccentric (now there's a surprise!) and had amassed a fortune of some £1.25million. He died in 2007 and after numerous personal bequests, the remaining £900,000 was divided into 100 shares. 25 shares (£225,000) went to C.H. to kickstart the Army Foundation and a further 25 shares went to the Scouts Association, of which £45,000 was to go specifically to the C.H. Scout Troop.
My interest at the time was in the Army Foundation and apart from noting the bequest to the C.H. Scouts left it at that. Some years later, however, (probably about 2012-13) I became aware that the Head Master (Franklin) intended to disband the C.H. Scout troop, which he declared to be moribund. I was surprised as the injection of £45,000 only 3-4 years previously should have provided some benefits. I therefore enquired of the then Clerk what had happened to Barclay's gift but was told that it had never come near C.H. as the C.H. Troop was self-administering and came under the Scout Association for administration, training, finance, etc. Thus, Barclay;'s £225,000 went to the HQ of the Scout Association and they were responsible for sub-dividing it as he had requested. In other words, as far as I could establish, that particular element of Barclay's bequests went to the Scouts Association and not to C.H.
I found the organisation of the Scout Association almost as impenetrable as that of C.H. but my impression was that the C.H. Scout Troop was answerable to the local branch of the scouting association (Sussex?). So, I presume that campsites, programmes, conduct of the camp, travel to and from, behaviour at, and so on were the responsibility of the Scouts and not of the school. (This would be similar to the CCF, where the school contingent is responsible to and administered, funded and equipped by the Ministry of Defence.)
Does that help or have I just muddied the water (again)?
David