First of all ... a belated welcome to the forum.

That's all good stuff ... but what
causes all those problems, do you reckon?
My guess is that the units don't get closed down properly, or the power cable (cord) gets yanked, or some such thing. Both equally daft, not to mention careless.
After all, I believe that Win XP is reasonably resilient. I'm not sure if it's as tough as Win 2000 ... but it's not as though it's really doing much here, is it? It just needs to be closed down with a bit of care!
But how to overcome all that? Am I right in assuming that there's no built-in UPS?
Maybe the real solution here is:-
1) Some way of disabling the main on/off switch
2) Hanging a UPS off the cart!
Of course, what is really needed is a ROM-based operating system (you know:- "instant on", no need to boot from disk, and good stuff like that) ... but I can't see that happening these days (unfortunately).
@Gerry: as recently mentioned elsewhere, sticky keys and tracker balls are almost always due to "sticky fingers" (that is, gel on the operator's paws)!