I am pleased as can be to report sauerkraut success. I opened the crock and carefully spooned out the nasty slimy gray stuff (still didn't look like mold but it sure didn't look like anything I wanted associated with food I was going to eat!). I carefully peeled off the blanket of cabbage leaves and looked down in at... sauerkraut! It looks just like the real stuff!
Next test - and the most important one, of course - was to taste it. Hmmm. Well, I don't think this would be a favorite at your local deli. It tastes... strange. A nice sauerkraut tang and great aftertaste, but that initial flavor... well, I don't recommend the cumin. I like that spice a lot, but I think not for sauerkraut.
All told I have just about 2 quarts. It is in glass containers, tightly sealed for storage in my fridge, where the fermentation process will slow to a crawl - enough to keep the sauerkraut "alive" but not enough to get even more sour.
I consumed a healthy amount of my experiment just now because strange flavor or not, it really does taste good. Therefore I am calling this project done, aside from washing the crock, weight plate and glass. Assuming I don't get food poisoning from my taste test, of course. Just kidding!