>> Forbidding the ending of a sentence with a preposition. <<
Many excellent writers end sentences that way, and the practice goes back centuries. In my opinion, when you end a sentence with a word like “with,” you are simply using that word as an adverb, rather than as a preposition.
Anyway, I think the “rule” in question is silly, probably imposed by 18th-century grammarians who thought English should be governed by certain patterns of Latin syntax.
You’re exactly right. It was impossible to end a sentence with a preposition in Latin (or to split an infinitive) because the preposition was given by the form of a single word (and an infinitive verb was also a single word). Thus, the early English grammarians said that one should not do these things in English, because they were not done in Latin.
Sometimes it works better to end a sentence with an infinitive, and sometimes splitting an infinitive just sounds better in English.
I learned this from a book called “Woe is I”, author forgotten.