The airspace on the routes over Europe weren't unopposed - flak and fighters were present over occupied Europe, radar enabled the Luftwaffe to track raids from their bases in England and plot intercepts.
Luftwaffe fighter strength in the western front was increasing through 1943.
Pretty sure...
It makes sense that the opposite rotation version had a different ratio, as there was an idler gear between the crank gear and the propeller gear.
I can't see how they could get 0.477 and 0.479 without an idler gear.
So, ego?
There was no need for him to fly.
Probably not for the group commanders, either.
I can see that Eaker's level would not have needed access to ULTRA directly - his superiors could do that better, and decide what information is worth acting upon.