I was at Bristol for the June/July period and every one of the questions you raised was covered there. I'll take question 4 as its a quickie.
To answer this question you have to appreciate the difference between a primary and a secondary radar. For a secondary radar, to double the range you would indeed have to up the power by a factor of 4. But in a secondary radar you are only interested in getting the signal out to the aircraft. The return signal is provided by the equipment on the aircraft using its own power.
The question however relates to a primary radar which has to reley on its own power to get the signal out to the a/c and back again with no assistance from an a/c transponder, hence it needs to be increased by a factor of 16.
I'm sitting in August. Wish me luck.
My applogies jinkster, that answer was for Q 6