The good news is that my printing problems have ceased.
The not-great-but-ok news is that, as anticipated, all of my principally unix-based software (most notably, my TeX tree) got shunted off to the side, and it’s easier to just go and reinstall everything directly rather than try to figure out what segments of /usr I’m safe in recopying from the previous systems folder. This isn’t so bad because it gives me the opportunity to upgrade all of the relevant software to its most recent versions anyhow, which is something that one should do periodically when said upgrades are available for free.