> How survivable is the F-35 when taking hits?
the point of the F-35 is that it is less likely to take these hits (hits which would destroy both planes) in the first place
> there is no need for CAS aircraft to face interceptors or other things that would shoot them down. They only have to worry about small arms fire.
exactly, so in a COIN scenario the super-tucano, which has a tenth of the A-10's operating cost and longer loiter time, is the better choice