Detergent & More.
I seem to remember something about there being a chemical in liquid detergents that can be harmful to the neoprene in Frigidaires. As for the loud spin (I haven't yet found the video) it might be a bad bearing, but I don't know which one. As for the lack of agitation, it could be seized bearings, a bent part, oil turned to grease, or some other problem. The folks here will know better than I will. The motor does come on and hum, so at least that is working.
Congratulations on your Unimatic. I hope you enjoy it for years and years. Also, thanks for sharing with us!
Congrats,
Dave