This is, what the xotcl request monitor does (including blocking). The basic units of investigation are URL paths (not acs objects), since one wants to monitor access on pages as well, which have no acs-objects associated. You probably do not wan't to have database operations in such a monitor, since it can easily become a performance bottleneck in busy applications. It would certainly be possible to support lazy (or asynchronous) database operations (at least, pgtcl 1.5 supports it) for recording, but in general, a streaming database would be the better approach on such bulk data.
Concerning the "installation on OpenACS.org of a package which sniffed around in administrative data and exposed connections which were otherwise hidden". All this includelet does is to present information available to users in a different way (in particular, the revisions information of editing pages). It is not so much different to clicking on a user's name in the forums.