Adrian
Re #5 the only "decent" picture I could find was in Clarke's "British Aircraft Armament: Vol 2". Though actually about the gun sight it does show the limited space available
Re: # 9, I couldn't say for North Africa (not too hot on this theatre) but in Burma, artillery and recon was carried out by a mixture of aircraft. One dedicated squadron was
656 Squadron Association (make sure you have the speakers off because the music is very annoying and I can't find the off button). In addition, a number of the RIAF squadrons, using Lysanders, and then Hurricanes, were used for artillery observations.
On the western front, a number of Spitfire/Mustang/Typhoon squadrons were assigned artillery observation duties, especially during the DDay/Normandy period