This gets to the part I'm not as sure about - I'll need to try it out. It depends on whether Seatalk echos or passes through NMEA sentences that it receives.
not as a general rule, and very unlikely to pass AIS.
The other thing that I know will stir up a lot of controversy here is I plan to buy a RAM mount to put my Netbook in the cockpit.
not from me
nothing wrong with using a laptop as long as you take reasonable care and understand any potential limitations. though for obvious reasons my opinion on software selection would differ.
I got my netbook splashed a few times, thanks to wakes of passing powerboats. It's still doing ok.