Thanks all. I thought I'd read somewhere that the Ambitions careers, both the new jobs and the self-employed options, don't work for uncontrolled households, but I couldn't find confirmation of that again. I'll try manually assigning a test Sim or two to one of these careers, make sure they have the items they need on their home lot, and try to see if they end up making any money from their new job while I play another household.