The lack of a printer system turns out to be that the system was configured to use LPRng (a BSD variant), while what was installed was CUPS (which isn't). Go figure.
The splash screen hanging around was, in fact, a Bluetooth daemon applet that was taking a long time to do its job - quite possibly because the machine had no Bluetooth-related hardware. Anyway, disabled that, and now the splash screen goes away. Hurrah.
Less joy on getting the colour printer to work. It's an Canon MP150, and looking around, it looks like the only way of getting Linux support is by buying TurboPrint.
Or by plugging it into the MacBook, and sharing the printer, which is what I plan to do. :-)
And it might be that this is just in time, since yet olde HP LaserJet has just started feeding multiple pages again, a precursor to it being chucked. Y'see, it's a "known feature" of this particular model that the feeder pad hardens over time, and simply stops working properly. HP said they'll give out one free replacement, and then you have to replace the printer. I had my replacement quite a few years ago...