As the crew animation was never the best (and maybe it's a pain to due with the SH game engine) I never wanted a ton of crew animation. It's not going to be the level of Half Life or anything I'd bet due to the game engine. I'd go for the SH3 level with reactions to depthcharges and add on some for damage\repairs. Of course if time and money wasn't an issue, sure go the whole nine yards
I also personally never liked the first person controls where you have to move to each room to issue commands. Always seemed gamey in other games and that's what you have sub comms for anyway. So I don't need room only commands to be there for the new rooms.
But having the rooms animated (with basic crew animation at their stations) would be cool. Like the rocking meat in the comms, torp loading in torp room, and the room chatter. In SH3 I used to move around just for a change of scenery while running underwater.
Also room damage animation with flooding is something I would have given my left nut for
. In that case having the captain there could be coded to improve the repair rate etc. In Das Boot it's the freaking crazy water pressures blowing into the rooms that I love so much. Having that and hearing the pings, the swoosh of the destroyer blades etc would have made all the rooms and animated damage so perfect for me.