I think that he was making general allusions at best, and that the more likely scenario is that through redaction, the authors of the New Testament quote mined. Malachi is perfectly clear, it does not apply to either John the Baptist or to Jesus.
No as I have said, you are perfectly free to believe anything you want. There are even people that believe that the Flood or Biblical Exodus happened. I simply am not convinced that the places you mentioned show prophecy has a dual meaning. Jesus was only speaking allegorically.
If you don't admit that, what other prophecy about Elijah coming do you think Jesus is referring to?
None. He was not talking about any prophecy. He was simply comparing John to Elijah.
Aslan is not a Tame Lion