Well, I carefully fixed the black grounding wire to the motor encoders and the system seems to work fine now. I got the AC motor to rev up quite quickly in neutral. Both forward and reverse movements are fairly smooth.
For yucks, I drove the car around the block. It has very slow acceleration, probably due to all the battery weight. I drove it in second gear. Third gear seems to not want to go in, at least while the car is stopped. The regen braking seems to work fine. The front end is rather heavy with batteries and the tires scrape something in the wheel wells when I back out of the driveway down the small cement slope on the curb.
There is much to do, but I at least know it runs and that I'm probably not going to race it at Nedra...
Off to celebrate with a brownie and a very much needed nap. Yay!