@Bingo

I meant this idea(s) from the first draft (or concept art) - giving the final battle some more weight, against as to why it would be in the middle of nowhere ...

as for Coruscant, Siege and Emperor: it would be interesting for the Rebellion to capture or kill Palpatine and since (if one keeps) the Siege in Episode 3 (or somewhere in the PT) it is easy to explain as to why the Emperor isn't anymore on Coruscant, "living" on a secret base (Korriban/Morriband?) - and remember the Senate was dissolved in ANH, so Coruscant is the toothless lion

The assault would involve Endor with the shield-generator (the idea to have the/a Jedi temple there is a nice one), the rebel fleet against one or more DS (because it would be logical to build more than one between ANH and ROTJ) and Lukes confrontation with the Emperor

for "the trap" would also mean, the imperial fleet could stand down, because there would be enough firepower in hiding and only a personal escort is present for Palpatines arrival ...