I did not change the pronouns because they are not "manly" enough. That would be ridiculous. Remember, these are only personal headcanons. I simply see Asmodeus as not particularly caring what people call him, and Levi being a demiboy - speaking as one myself.
As for your other point - there are routes planned for this rewrite as mentioned on the first page, so the harem from the og isn't going to be there. Hope that helps.