Thank you. Now in answer to your question, I don't really subscribe to any of the three positions you offer. However, since that's not a very informative answer, let me try to explain where I disagree with them.
1. God gave Joseph the exact word for word translation into English of exactly what was etched into the plates.
I would say that this is the closest to my personal position - however, it seems evident to me (from the position as a believer) that this cannot describe the quotation/reinscription of the KJV language in some places. So, while noting that I believe that there are exceptions where other reasons lead me to conclude otherwise, I would follow this option.
2. God gave Joseph a word for word translation into English of what He wanted him to believe was written on the plates.
I don't think this is a very useful description because Joseph believes this is what is written on the plates whether or not what he received was related at all to whatever is on the plates. That is, he might have received a work of fiction (ala those who believe the Book of Mormon is a work of inspired fiction) or he might have received a very literal translation, and in both cases, it might be argued that God gave him what "He wanted him to believe was written on the plates." In any circumstance this might be true. Although in some cases, we might question whether it was a "translation" even if it was given word for word, and Joseph believed that it all came from the plates.
Obviously, given that, option three doesn't have a lot of meaning for me either.
The difference between formal equivalence and dynamic equivalence is over what we see. Does God alter the text to produce a better meaning for his intended audience, or does he try to stay with a stricter sort of word based translation. In some ways, I see both issues at play based on examples from the text. So, I see elements based on the text of the Book of Mormon that I would associate with a more literal sort of word-for-word translation, and some places that I suspect a more dynamic equivalence. And in some places, I am certain that what the Book of Mormon contains does not represent a word-for-word translation of the gold plates.
Ben M.