catch, the abarbanel is in yeshuos meshicho, when he deals with the ramban’s vikuach extensively.
re, rav hirsch, etc…, they do not say, chas me’lehazkir, that a word of chazal is not torah misinai. Kol ma shetalmid vasik asid….was said at har sinai. What rav hirsch writes is that strictly speaking there is no obligation to LISTEN to chazal in agadata, but that we would be foolish not to.
That dovetails the discussion among rishonim and achronim about what the authority of chazal actually is. Is it a din, or is it the understanding that we are nowhere near on the level to argue with them? There’s a famous beis yosef on it, who says that klal yisroel were mekabel the gemara. Rav Hirsch holds that it’s a din by halacha and not by agadata. That has nothing to do with saying other pshatim.
When achronim on chumash say pshatim that dont fit with every single chazal(there are a myriad shitos in midrashim, and you cant match them all, or even most of them) they are not, chas veshalom, treating chazal as recommendations, and not torah misinai, they are saying torah lehagdil torah vela’adira.
See the first bartenura on Avos, where he says that avos begins with moshe kibel…, to show that EVEN ethical aphorisms and teachings are not something that chazal said on their own, without a mesorah, but rather EVERYTHING was mesorah.
“kofer bedrashos” includes someone who denies techias hamaysim; according to the way you’re understanding this issue, if one argues with the drasha of Az Yashir Moshe, he is entitled to, since it’s not a halachik issue.
This is part of what makes rav hirsch’s explanation difficult; but we don’t change the “pashtus”, pardon the pun, of kol ma shetalmid vasik etc…, based on something rav hirsch said – happens to be that not everything in the collected writings is even from him; there were letters not in his handwriting which his relatives decided were written by him. Truth is that anything outside his published seforim(19 letters, chorev, etc..) I would take with a grain of salt.