User, the rishonim write how the frum jews used to call each other Rabbi to distinguish themselves from karaim… So the practice continued.
Damoshe, there’s no “machlokes” – you’re mixing up the yotzros.
We’re not discussing relying on a heter which you think is wrong. Talui al beis din patur is a sugya in horayos, and if you’re fit to know when a psak is wrong, then the halacha is that you can’t apply talui al b”d.
None of that has to do with lo sasur. Check out the chinuch on the mitzvah; it’s about emunas chachamim. We listen to the teachings of chachamim and don’t think that we know better. We don’t argue with people bigger than us, etc..
As for political matters, it is another invention of MO that claim that it’s only a new phenomenon. Josephus, no fan of chachamim, writes (quoted in rav avigdor millers hashkofa seforim) that all political offices were sanctioned by the rabanim.