Oops, missed one:
When is the F/A-XX needed?
It's needed to replace Super Bugs as they run out of flight hours. I'm sure the exact numbers could be found if a person knew the correct questions to ask, but the last Super Bugs will be delivered in 2027 (as currently bought). Call it 20 years from there means the
LAST F/A-XX needs to be delivered in about 2047. Might be able to stretch airframes another 5-10 years, IIRC the Blue Angels birds are ~20 years old
when they arrive. So the last FAXX might be able to be delivered in 2057, if no wars happen that deplete the Super Hornet supply and the Navy thinks they can get away with running the Super Bugs that long.
As of end of 2023, the USN had 421 Super Bugs in service, with 76 more on order. And only 30 F-35Cs active with 204 on order (I was expecting more, but I guess the rest are USMC). So,
~500 FAXX assuming 1:1 replacement of Super Bugs. That said, the USN was also looking at replacing some aircraft with UCAVs, one of the proposed Carrier Air Wings was only
a single squadron of FAXX, the rest of the strike planes were all UCAVs (3 squadrons). So that'd bring the total needed down to
as few as 132 (12-plane squadron, 11 carriers in service), but I have a better feeling for keeping about twice that. 264-288, upper number for 12 carriers in service. Call it about 300 with the Blue Angels also rocking a squadron of FAXX.