Just got RSRD and TMO installed. Questions

So I played it a little bit and I figure I may as well try out this fleet boat thing and I have to hand it to Lurker and the TMO modders, it makes the game look much better, I have questions though (As I am used to GWX and ShIII) what big differences should I be looking for? I hope Im correct in that RSRD adds much more shipping and such?? And could anyone give me the Crush depths of the classes of american subs?? as well as if you pass crush depth you can only sustain it for so long before finally being crushed? or do you just poof die as soon as you hit it??

And what other things should I be looking forward to?? (I only got to pull out of pearl and had to quit.)

and finally, any other mods that I could be adding?? (Stuff like better UI's and such)

Sorry for so many questions guys. Wish me luck! Im gonna try out this PTO thing for once

Casey