First off, let me welcome you to the most salty forum on earth!
There are mods that address most if not all of the issues you mentioned.
If you start with one of the mega-mods like:
NYGM ;
GWX Gold ;
Living Silent Hunter ;
you will have most of the things that were lacking in your Vanilla game.
All of those Mega mods make Silent Hunter more accurate Historically and graphically better.
They all have their own fix for the Weather. Better AI, better Planes and more ships and units and even simulated Wolfpacks.
On top of that, we here at Subsim, kindly recommend the Patches and Realism Fixes for the sh3.exe provided by h.sie and Stiebler.
Which will even more enhance your experience.
Explore all the stickies on this board and you'll be ready to go.
Propaganda out.
