HaLeivi: I am not sure why you mentioned in your recent comment- although I venture to say that you maintain that the disucssion of playing ball on shabbos (and the subsequent quote fro mthe jerushalmi) have nothing to do with the subsequent discussion of believeing in “mmamaorei chazal”. I agree totally- these are quite differetn subjects that, somehow, were mixed together.
As far as responding to DaasYochid- I agree with you the Tannoim and Amoroim have a special authority. The question is whether this extends to science, astronomy, medicine,etc. I dont’know whether “sod Hashem lejereiov” covers that.