Yes, you're correct. This type of sentence happens because we are allowed to end a sentence with a preposition in English, whereas in most other languages this is forbidden. Therefore it often sounds strange to English learners. Essentially, a sentence such as "Who are you talking to?" has the same meaning as "To whom are you talking?", but ending with a preposition is a lot more common in spoken English. The second question sounds quite old and outdated.

yes, you are right. Maybe there is a typo "Let's LEAVE them a proud ...." I suppose "cleave" could work in context, but it is unusual = "Let's leave a trail of blood they can find us by"