It only has a QVGA screen, and that'd put a damper on using it as a mini-PC. Also, I don't believe it has VGA out, only composite/S-Video.
Closed source Z apps would need their environment the same as a Z. If you don't know how to setup GNU Qtopia that way(compiliers used, settings, etc.), I wouldn't bet on closed source apps working.
Why do you have, and carry, two laptops?