So the solution to not being able to afford F-35 and cats'n'traps is to buy F-18, cats'n'traps and F-35. I think I see the flaw. F-35 isn't magically going to get cheaper.
Agreed F35 is not getting cheaper. F18 would not be the route we would take had F35 been developed on schedule. It is a pragmatic response to the risk of having aircraft carriers with no aircraft for an uncomfortable period of time. If during this 'downtime' something delays or worse still, brings F35 to a halt, then PoW will be taking up a lot of space and looking for a secondary role or another home.
F18 is '4th generation', which seems to carry a stigma. However, I guess that just puts it in the same class, or higher, than 95%+ of all operational fighters until well into the 2020's and likely longer. If it ain't stealthy back it up with some jamming - Growlers would be good.
You are right that adding short-term expense by buying now rather than later will be very unpopular with the government and is the main reason why I don't think it will happen. Hence why they will probably take a gamble on F35B - if for no other reason that short term expense on EMALS will be avoided at the risk of the B being cancelled, again leaving a carrier without a fighter unless we then retro fit EMALS. Goodness knows how much that would cost. But these nightmares are deferred for a while and a problem deferred might land on someone else's desk. It's an awful mess frankly, which, if solved, will depend upon a big dollop of luck as well as judgement.
Australia have taken the F18 route while they await F35 but they have not suffered as badly as we have in the financial crisis and are fearful of regional threats developing from the north. And the US Navy have ordered more F18's, so it's good enough for the best naval strike force around. And it would certainly be a step up from the UK's current naval strike capability, land based Apache helicopters flying off of Ocean (and no, I'm not having a pop at Apache or Ocean).
..I am hoping this ministerial silence regarding the decision to change tact and go back to the 'B' is a good sign..
I think the silence is down to the fact that the Cabinet has lost confidence in the MoD's ability to cost it's alternatives properly and so the Treasury has been asked to audit the whole process. So we wait for their input. Which is why I think it highly likely the answer will be to opt for the lowest short-term expenditure - no CATOBAR conversion and therefore F35B.