^all of these ideas make sense.

for the ending, how about the celebration continues as usual, but we only see the ghosts of obiwan and yoda, luke then proceeds to burn his father afterwards, then pan up and end.

check out my idea for TPM ending, it would be quite similar: http://www.youtube.com/watch?v=VU2jga_fbnE

i think the emperors shuttle should be something COMPLETELY new, maybe something more yacht-ish like the solar sailor dooku uses?

SSWR did some mockups which follow a similar vein to your ideas, such as the stormtrooper armour and the lightspeed ending. did you ever see any?