Excellent answer jwilliams
I will add (
in blue):
1. Can I find a updated keyboard layout somewhere - only got the one from the manual on disk.
Press F1 while playing to bring up the Keyboard screen.
2. And is the no "search pattern" to plot - when you come to the patrol zone.
Sorry I'm not really sure what your trying to say, but.....
Stock SH5 does not have search patterns, you have to manualy set a search pattern.
Search pattern are still in the code, but if reactivated they would work once but produce a CTD the second time. (hope this will be fixed)
3. Sometimes I can"t go "rig for silent running" why could that be?
You must have you engines on the lowest speed to be able to rig for silent running. maybe your going too fast?
Could also be linked to the morale bug..... hoping the next patch will fix. . Theres a mod (check download section of this site ---> LINK ) to work around the morale problems until the patch is released.
Also be sure to be underwater, as Silent running is not possible when surfaced.
Oh and welcome aboard 
Yes welcome aboard 