With an i7 and a GTX480 with 1536MB RAM, you should be having no problems coping with any aspect of BoB2 hardware challenges.
Regarding the screen display, you may benefit from playing with the GUI setting "Use desktop resolution" - try both settings and see if either helps.
If we solve getting the image across 2 monitors, you may find the BDG.txt variable
ALLOW_ULTRA_HIGH_FOVS=ON to be useful, it will reduce stretching across the wide aspect ratio.
seems the video show when selecting mission only works with BOB2 in compatibility mode
Yes, but the general consensus is that other things seem to fail in that mode, so you are best to just install and run directly in W7. you won't miss the videos after the 10th time you've seen them...
The crashing after takeoff is most likely due to using compatibility mode; at least, that has been the experience of a couple of users recently ("crashes within a couple of minutes"). Try running without it as a first adjustment and let us know how you get on.