A:AnswerI don't know the measurement but there should be no reason to cut out the wall in order to mount it. The mount keeps the TV nearly flush to the wall as it is.
A:AnswerMy first answer would be because it's Sony :) In addition to that it is well built, fairly simple to install properly, and it's super flush to the wall. I bought it for my 77" A9G OLED TV because, well I spent so much on it I wanted the best mount I could get for my Sony TV. Even then I believe I used some Amex points or rewards points from Best Buy because I just couldn't stand to pay that full retail price for what it basically a no frills mount.