As for starting the external programs:- only Win32 programs are supported (NO Win16 and NO DOS). Raman, you're right, we've also noticed that sometimes, launching such a program from the command-line causes it to close. We can take a closer look at it - but I'm not sure there's something we can do about it - it's just not supported...
- if the program is Win32, it needs to be quite resource- (and API-) modest -- in other words, only "leightweight" apps have a chance to run...
As for the swapfileNo, I don't think there is a way to set up a swap file in BART. Therefore, you need quite a bit of memory (64M is a bare minimum, 128M is recommended) to do some serious stuff.
As for the TEMP pathSure, why not. You know the SET commnand, don't you?

Just use it from the command-line tool to set the TEMP path to anywhere you want... There really shouldn't be a problem.
Hope this helps,
Vlk