VB vs. C++?!!!
Well, VB is a so-called RAD [Rapid Application Development] and it wouldn't hurt for it to be 'ported' to Linux. On the other hand, it's speed leaves a lot to be desired :((
C++, which I think is the best language available (free or not) is much more flexible and a lot faster. Maybe VB is simpler at what it can do, but I'd like to see you try to use pointers in VB... (it can be done... but I'd like to see a guy who made it all by himself :)) )
As for python, I wouldn't worry... It's made in C, like the whole linux kernel, X, Qt etc. That shows what a good C programmer can do with it, right?
My half of cent :)