sorry my OP was _way_ incomplete. my cut and paste only pasted the first two lines or so.
I was getting 58v on illum and trad switches when off, Zero when on.
Leviton said I had a floating neutral
Rough-in testing had been fine. although the 58v had been at the fixture leads too. Turns out Illum switches pass current through even when off. Apparently a no-no for appliances and/or led.
I'm using a trad flip switch now.
On the positive side I've got answers:
First: my ignorance betrayed me (again). For any future DIY'ers: How do you test current flow at a wall switch? NOT: by metering the two brass connectors. YES: lead on the incoming hot, other lead on the ground (when the outlet is off)
YES: lead on the outgoing hot, other lead to the ground (when the outlet is on)
Second: Ya gotta think , ignorant dude: When I checked the wiring in the ceiling fan I found: my hot/red lead was connected to the fans white/neutral my black lead to the fan's black lead. I read the fan instructions too literally while not thinking. Now I have it properly wired (my hot/red to the fan's black, my neutral/white to the fan's white and my black is dead/unused.
Hmm, I feel so much better.