You say the Navy (RN) isn't the flying force, well no, but the Fleet Air Arm is. There are very few non flying jobs for Aircrewman.
Have the people you have met actually had careers? If so, it's a shame and a surprise they stayed so long when they weren't happy. We're they Aircrewman? Most, if not all Aircrewman I know that have left Liked, if not, Loved their time in. They all left for different reasons, as people do in most jobs. They've all gone on to be successful in second careers as well, most in aviation related jobs. Some left after 15 years or so, others full careers of 22 and the remainder beyond 22, so something must have been right.
RN vs RAF is a tough decision that only you can make but gather all the information and talk to the right people. Especially on the WSOp famil and get their views on both rotary RAF and RAF fixed wing. What about the army?
As for going to sea, your deployments as an Aircrewman may be less than general service but expect this to change with QE and P of W. Personally, I think this is a good thing, my best career times have been at sea and most would say the same. Currently amongst the more junior sailors (non aircrew) that I talk to, they are disappointed that they are not getting away on detachments and deployments more often. Come next year, with QE deploying I think they'll find what they been missing. Which are run a shores, preferably somewhere warm with a nice beach!
Flying and operating embarked is different, maybe more challenging than from ashore even for non pilot aircrew. Having experienced fixed wing MPA flying, even on a busy ASW sortie I was bored in an hour or so and was happy when the 6+ hour sortie came to an end. For me it wasn't the same as tactical mission flying in a Merlin, it lacked the thrill and excitement that I'm used to on that type of sortie. It was very comfortable though, nice and warm and they had a toilet. I couldn't comment on Chinook or Puma forces, I expect it's pretty good but no more than flying Merlin in CHF.
Finally don't get caught up thinking more flying hours will help in a subsequent career, probably quality flying exceeds quantity.
As well as choosing based on logic and location, career prospects etc don't forget to select on fun. If there's no fun you probably made the wrong choice. Good luck and more than happy to answer any further questions.
