Great effects work, I like it!

The Revenge outline is good, but I think its too ambitious given the existing footage.

I like the idea of Han’s sacrifice, but you don’t have reaction shots or dialog from Leia, Chewie or Lando to support it.
But if they all die on the explosion then Luke’s reaction is enough.
So my suggestion for a darker ending is have the entire team killed on the explosion…

A simple lighter option is to have them plant the charges and just run before they go off.