Tourist,
I agree with some of your points - the advantages of a full CAG at sea are very alluring and I've always believed as an island nation that we (UK) missed the boat (excuse pun) by taking a capability holiday in that area. What the FAA have done to maintain expertise in the carrier environment will hopefully pay dividends as our first carrier arrives at Portsmouth in a few years time.
QEC, with up to 24 F-35B aboard, will undoubtedly give the UK a larger remit of choice. The government must ensure both ships are comprehensively protected when they sail; something that has been alluded to earlier. In the shorter-term I can only see a QEC sailing as part of a larger USN-led task group if going deliberately into harm's way. We can do the plain cruising around part ourselves, but Th entry etc is another matter.
Shame there's no cocktail deck on her for when she isn't on ops but I'd also point out to those reading that aren't familiar with maritime ops that even a carrier needs replenishment at sea so logistics touch everything.