Man, that's some thought. If they pulled that off, then I'd be satisfied.
I had the WEIRDEST thought for an idea for an ending:
Locke, Jack, and Kate are the only ones left living when help somehow arrives, but Locke's in rough shape and is in a coma and stopped breathing or something.
Point being, they get on the whatever that saves them and are asked "Are there any others?" before they leave, and Jack says "No."
Kate: What about Locke?
*pan over of the island as you see the plane/boat that saves the two take off and it shows you the wreckage still left from the crash, and then some of the bodies and then a close-up on Locke who is pretty much dead.
Close up on his face...and his eyes open.*
End.
I know that wouldn't make sense at all because they'd want to go through all the other bodies and not leave anything there, but still. That would be freaky.