I am sure this has been covered by others before (so apologies in advance) but what I would like to see is a separation between Naval Bombers (the likes of SBD Dauntless, Fairey Swordfish, etc) which are there to attack enemy ships (with a small anti-sub capability) and Patrol Bombers (PBY Catalina, Shorts Sunderland, etc) which are very long range patrol planes optimized for long endurance and enough payload to carry adequate anti-sub munitions. The current Naval Bomber tries to do both jobs, and particularly for the LR recon, does not do the job well so I would propose:
Naval Bombers - pretty short range, optimized for surface ship attacks, carrier capable, with some anti-sub capability - so pretty much as they are now but with reduced anti-sub and lower anti-sub detection probability
Patrol Bombers - long range flying boats (mostly), with very long range, good anti-sub capability and some sort of ability to detect subs (not automatic but if on patrol then perhaps they get better and better info about their patrol zone). Perhaps you would be able to base these at any coastal province (given they were mostly flying boats). Or even a research option to do land-based LR naval recon planes (B-24 Liberator, Fw-200 Condor) which would be "cheaper" because they are derivatives of existing land planes but would need an airbase to operate from - even a situation where you could cheaply research a LR land-based naval patrol bomber directly from a strategic bomber (ie each level of strategic bomber would have a link to the same level of land-based patrol bomber) whereas flying boats would be a separate research line - more expensive but more flexible
Then, of course, why not have long range land-based high altitude recon planes - like the Ju-86P, stripped down PR Spitfires and Mosquitoes. These would have no offensive combat capability but would be very difficult to shoot down early in the game - basically being immune to similar or lower level Ints and with higher level Ints getting a chance of damage. Then players could run recon missions without using combat planes. Recon missions over neutral territory could be run with little risk of detection - make them like subs ie stealthy with perhaps a chance of detection?
To my mind these would add a further dimensions to the game which can only add to the enjoyment right?
Naval Bombers - pretty short range, optimized for surface ship attacks, carrier capable, with some anti-sub capability - so pretty much as they are now but with reduced anti-sub and lower anti-sub detection probability
Patrol Bombers - long range flying boats (mostly), with very long range, good anti-sub capability and some sort of ability to detect subs (not automatic but if on patrol then perhaps they get better and better info about their patrol zone). Perhaps you would be able to base these at any coastal province (given they were mostly flying boats). Or even a research option to do land-based LR naval recon planes (B-24 Liberator, Fw-200 Condor) which would be "cheaper" because they are derivatives of existing land planes but would need an airbase to operate from - even a situation where you could cheaply research a LR land-based naval patrol bomber directly from a strategic bomber (ie each level of strategic bomber would have a link to the same level of land-based patrol bomber) whereas flying boats would be a separate research line - more expensive but more flexible
Then, of course, why not have long range land-based high altitude recon planes - like the Ju-86P, stripped down PR Spitfires and Mosquitoes. These would have no offensive combat capability but would be very difficult to shoot down early in the game - basically being immune to similar or lower level Ints and with higher level Ints getting a chance of damage. Then players could run recon missions without using combat planes. Recon missions over neutral territory could be run with little risk of detection - make them like subs ie stealthy with perhaps a chance of detection?
To my mind these would add a further dimensions to the game which can only add to the enjoyment right?
The problem is that people normally don't want to invest so much in NBs to have enough to compete with a navy, but yea, a nice 5 stack mixed with other planes can take care of a sizable local threat. 
