The only problem with this is you don't get the great shots of Luke looking out the window at the battle raging below. I don't know if they're essential to the plot, but they may be difficult to edit around.
No, the battle would still be over the DS like the original. I think there are even elements of the DS2 in the existing film that are about the right size.
You guys can do it. I know you can! Really amaze people with this! Blow them away!
EDIT
Another angle on this goes back to what someone above said about the "sanctuary moon" as an Imperial park so to speak...a place to tame and control.
Wouldn't it add some depth to have these little ewok buggers help take out the imperials right from under their noses? It drives home how arrogant the Emperor has become, as Luke alludes to when he meets him: "your arrogance is your weakness".