my tendonitis pain intolerance is close to exceeding my $AUS1000 price tag intolerance, so I may be buying a smartnav soon

A couple of minor questions:
1) If I buy a TrackIR I can't use it for the windows desktop, I know. But if I buy a SmartNav for work I'll also be able to use it for games, right?
EDIT: This was answered in another thread I asked a while back, but some forum posts infer that I can't due to a lack of auto-pan in the SmartNav software.
2) I know the extra features of version 4 over version 3, but how do they compare in real performance terms? If I can find a v3 I could get it now, whereas I may never get the money for a v4.
3) is it possible to use TWO double-switch foot pedals? ie give your feet the ability to enter in four key combinations?
EDIT: never mind, I found that you can buy three pedal system that you can expand to 4.