I've wondered the same, too. If they ever release a DVD set I guess the info will be there.
If they redo the cast, I don't believe for a second they would let Lili go. My money would be on Minka.
Nah, I love the show, flaws and all. And like all lovers I wait for the day it will get better. ;)
I'm not sure how doable is to fix some things after they were shoot. A small scene here and there, maybe. But then writing is/was a real issue, so...