To hal,
I don’t draw any conclusions from the gemara with acher.
Different time periods require different attitudes towards these issues. Everyone has their own border they won’t cross, everyone has their own slippery slope and everyone thinks they know who the bad guys are and who the good guys are.
Today I read a pashkvil put out by a well known and large chassidic sect, forbidding listening to or reading the seforim of someone who Rav Kaniefsky shlit”a himself proclaimed to be the godol hador. What does one make of that?
Unfortunately, the Torah observant world has expended so much energy in paselling everyone else, that no one is left. We’re all pasul. Kofrim. Assurim b’maga u’tmei’im b’ohel. Sad, isn’t it?