Good for you, Max!May I also point out that someone purporting to be a representative of one of HFA's vassals signing on would mean that they should know full well that they have already accessed the list that they request?
"Publisher"'s letter creeps me out. It sounds very much like "You are doing this to yourselves. Stop being fussy and knuckle under already." Notice also the unsubtantiated claim that "You DO have such copyrighted material on this site", yet also the refusal to state WHAT material is found to be offensive... only the repeated absurd demand that a full list be submitted to them. They've obviously decided to pursue escalation through pure intimidation.
Max, though I'm unable to financially help at the moment (soon, though...), best thoughts and wishes for this. You are an intelligent man, and I know that whatever course is chosen will be the best. May the muse that guides us all protect.
M