MrDave...
Su-27 and Mig-29, whilst they do indeed get airborne from carriers, and doubtless are very feisty once they have, can also carry about as useful payload as a small flying fish in the process. Typhoon likewise would doubtless be able to get airborne from a carrier with a ski ramp, but a useful long range A-G payload sans catapult? Hmm.... as you say, only solution is to have AAR, which for UK PLC is going to mean buddy-buddy if you want a reliable form of carrier AAR, as the VC-10/Tristar/A-330 PFI are not always going to be avail. Buddy buddy means half the useful sortie rate, which is not ideal!
As for landing back on, it's not just as simple as re-jigging the gear to make it strong enough. Either you strengthen the whole airframe, or your fatigue life of the jet has just been hugely shortened.Even more so if you actually want to land back on with anything hanging under the wings.