Eventually this got worked out. Not sure what the silver bullet was but I changed bushings, checked and swapped some front and rear lower control arms, checked front uprights to known good ones, brake calipers, re-did alignment, measured subframes.
The one thing that I didn't change was the upper front control arms b/c they had been 'blueprinted' by a pro shop for camberz. This could have impacted caster but I never got around to checking. I will be swapping to stock FUCAs with the bushings one of these days...