OK, for starters, I was on the SSBN 620, a boat that got turned into razor-blades quite a few years ago so what I say may not be applicable now.
As far as norale goes, it really isn’t “kept up” in any formal sense. There are very few morale-raising attempts aside from half-way night where people used to gamble and put on entertainments for each other. (The gambling money went to charity so it wasn’t a problem)
We did work out with weights. We brought a bar and got the machinests to drill-out some trash-disposal-unit weights. We then got a small bench-type locker and did bench presses and the like. We got around the noise part by using a lot of pillows and blankets under the bench as a just-in-case.
As far as the rest of your ideas go, they are pretty good.
Sub duty is always voluntary although once you volunteer it is difficult to claim you were just kidding and go back to surface ships. 
Discipline is odd on an FBM. In some ways it is very lax while on patrol in that people tend to get shaggy, wear funnny hats occasionally, and things like that. There is very little spit-and-polish. Also, the officers are not the remote sort of demi-gods they tend to be on surface ships. There is no room to maintain that image. OTOH, there is little need for such official discipline. Everyone knows their job and tends to do it without being forced to do so. It will probably upset the surface warfare types and I admit to a bit of bias, but sub crews have always seemed a cut above the rest of the navy.
The food is as good as it can be. Of course you run out of fresh veg and eggs and milk and the like but they do try hard.
As far as “Crimson Tide” goes, I hated that movie. The representation of submarine life was one step away from the seaview and I’m surprised they didn’t have a “flying sub” aboard somewhere. The other thing of course is that the war department does NOT send things to the Captains saying they might want to nuc someone soon. You either get the doomsday message or you do not. Captains do not decide to obliterate someone on their own hook. Besides, they couldn’t do it anyway.
I was on patrol when the Iranian revolution broke out and there was loose talk about flattening some cities in Iran. That was ther only time in five patrols that I ever heard the CO come down on people for such things. He didn’t even want people talking about such things and he was as warlike a man as you’d ever want to meet.
People keep up their own morale. I did a lot of reading. I remember reading the Lord of the Rings and deliberately limiting myself to a few pages per day so it would last. I played a lot of cribbage and spades, usually not for money, just bragging rights. Then there is the “patrol calender.” In my own shop someone would build a calender on a large sheet of graph paper and someone would fill in the day with a picture of some sort every night. These were very popular. Talking was good. I made some very close friends on patrol. As my ex-wife pointed out, I spent more time with my crew mates than I did with her. True enough, but hardly by choice. S Sleep was also a popular choice. One guy claimed to have slept 18 hours once. Aside from that, planning what you were going to do with the SO when you got home was also very popular although not (usually) discussed openly. After my last patrol we didn’t get out of bed for three days. LOL
Some people were unable to keep their morale up on their own and went nuts. A guy did it on my first patrol. He was religious and got into the habit of talking to God. Eventually, God started answering and telling him to do things. He (the guy, not God) shut off the oxygen generator once and about that time he was declared dangerous and locked up. We kept him in a straight-jacket and doped-up for three weeks until we could get somewhere to helo him off.
I hope this was what you were looking for.
Testy