There is a collection of "minor tractates" some of which contain material not found in other works of torah sh'baal peh (the oral law). What is the origin of these tractates? Who wrote/compiled them? ...
If someone says "I believe that the Mishnayos/Braisos/Toseftas are accurate, but I think that the Gemara made mistakes and has no holiness. Is such philosophy heresy? What about someone who argues ...
We don't have (and more's the pity!) R' Yehudah Hanassi's autograph copy of the Mishnah (well, okay, it's a controversial issue whether he actually wrote it or only arranged it orally), or Ravina and ...