Rav Pam’s psak: Anything with an actual Name (the 7 sheimos sh’ainam nimchakim, plus the kinnuyim that we pasken are Kadosh cf RaMBaM yesodei Torah ch. 7) or a pasuk from tanach with or without a Name goes in sheimos. There is no din lishma. All other divrei Torah, regardless of language and ideological purity of the author gets disposed of respectfully but does not require geniza.
If I were you I wouldn’t go through the entire pile of reform scholarship to see what is Torah and what isn’t. Just dump the whole pile in paper recycling and be done with it.