At last 1 that I think I can answer:
1. He was called Jasper Maskelyne.
2. He was a stage magician before the war.
3. To hide the Suez Canal be constructed a rotating cone of mirrors, creating a wheel of spinning light, some 9 miles long. The intent was to dazzle German pilots so that they dropped their bombs off target. (Interestingly enough, the British Army were still looking at the use of light for camouflage in the early 90's.)
4. The unit were nicknamed the Magic gang, not too sure what their official designation was.
Great question, certainly had me plumbing the depths, need to go back and reread by Boys Own comics!