It's an interesting idea, Rich, and it does work, as I've proved by trying it on my Arch machine. It also has the virtue of writing only the particular information I need to the log file, thus keeping the file from growing to large proportions. And it could, furthermore, be quite workable in this particular situation, since there's a fairly limited number of programs I allow users to run (maybe 10?).
But there's a problem implementing it due to the non-standard design of TC. I cannot, for example, make persisting changes in /usr/bin (the location of most of the programs whose use I want to track). Then, there's the problem of things allowed/disallowed to appear in wbar (wbar is the only menu on these machines, incidentally). I know there are kludgy ways to deal with this: I could, for example, make a bunch of scripts in /mnt/sda1/tcelocal that would do the job, then, using wbarconf, remove the icons for persistent applications I've installed and replace them with icons representing the scripts I created. But that's a really convoluted and ugly solution. And I know I could accomplish something effective and similarly kludgy by adding various entries to bootlocal.sh. But I think I'll hold out and see whether something a bit more elegant and straightforward might be possible.
Then again, maybe I'm misunderstanding something about your proposal? Further input on this, Rich, or anyone else?