So, reading through all this, those of you who are relatively low income may really benefit from starting with the IRS Free File site. It let us file federal and two different states with an HSA, spending from same, weird student employment exempt from FICA (him), investment income (some qualified, some not), foreign taxes on same, and two different self-employment scenarios (me).
Possibly relevant: every time I saved and came back to it later, I logged back in through the free file site just to be sure to avoid any shenanigans.
https://www.irs.gov/filing/free-file-do-your-federal-taxes-for-free