Do I answer yes or not to "Did [this work] involve work (1099-misc) that's like [taxpayer's] main job," as I'm retired?

If the 1099-MISC involved compensation for "working" (including providing goods, personal services, consulting, etc.) then say yes.

The question is trying to figure out if the income is "unearned" (like a contest prize, a student stipend) or "earned" from "work."