Hi rick, welcome to SubSim.
To answer your questions,
1. The games have difficulty settings so you can work your way up to hard core realism.
2. I play on a laptop with a wireless mouse. No problems.
3. Can't answer that as I play 3+GWX +lots of mods.
Check out these...
http://www.subsim.com/radioroom/forumdisplay.php?f=202
http://www.subsim.com/radioroom/forumdisplay.php?f=244