I think it works well without the force ghosts, Vader has been redeemed and i think burning vaders body on the funeral pyre - serves as Luke honoring his father.
Its nice to see things done differently here, just my 2 cents.
Also spence mentioned there will be no force ghosts in the entire movie...so Ben's ghost is gone too? ...would be interesting to see how the scene plays out on dagobah without him.
Edit: I've had an itch to try out editing for myself for ages, and its getting worse the more i see cool stuff on here! I guess getting a copy of vegas would be a good start as most of the stuff i would like to try first would be trimming and cutting scenes and altering the audio tracks.
I can understand the effects work being pretty complicated! but i hope you manage to pull off the stuff you want to do Spence!