If no one has mentioned it yet...
Bring back the interactive crew. As they are in SH4 now... they kind seem like mechanical mannequins. (if I spelled that right)
Hitman "hit on" (LOL!) some of the other things that concern me most.
Oh yes! Please cause the sensors to be
unable to 'see' through land masses... and DO cause active sonar use by the player to be detectable by the enemy AI. (Atlas Eschalot etc.)
Also it would be good I think for the enemy AI to be able to detect blowing ballast and torpedo launches by hydrophones. (in favorable conditions that is...) Also, a DD running at high speed shouldn't be able to hear much of anything. IIRC, underwater sensors were pretty much unuseable at 15 kts or above.
Tis enough for now. Time for me bed.