Newbie questions
 

There is a mod that makes TC go to 8x with all ships? Because in SH5 time compression only goes to 8x with enemy ships, and in reality all u-boots had to verify the flag of all ships that they encountered.
And why in SH5 all ships sink from stern or bow, never roll sideways like in SH3?

I don't believe there is a seprate mod for this, though you can adjust this things in TDW UI mod for sure.

But you can try editing the main.cfg file section responsible for the TCx