Did you sell the furniture or pack it with you?
Sold it, as per the dynasty rules he left that house with nothing, left the doll on the bedroom floor and sold the house with furniture as his parents were both gone, had no doll when I saved the family to the bin for moving but had it when I put them down in Sunset Valley, as I said they are just odd
I just tested that theory of making a pre dead playable first, that worked fine for keeping them in the family tree, having played about with Riverview in CAW I know all the dead sims are in random households together and in the empty houses about town, when you start a new game they get bumped off and assigned to their respective tombstones, I guess that makes the game not see them the same hence it not working when you move.
I had a play about with the lots while in Sunset Valley, I put a 64x64 in the water and just to see if I could stuck the movie studio on it, I was curious if it would get automatic stilts underneath but it just pulled the ground up
Shame as I recently got Serenity Retreat and had visions of putting it out on the water but it wont work as I'd hoped.