those false negatives are also growing an AWL, which I also don't want.
-1.4 AWL AWL: From: address is in the auto white-list
how do I disable and purge any AWL and ABL generation, too?
Well, there is no "ABL" just one system called AWL which works as both white and black.
Disable it with: use_auto_whitelist 0
You can purge it by removing the database files with rm -f. They should be in ~/.spamassassin/. Be sure SA isn't running when you delete them.