So far in my vanilla game I have seen a lot of families moving out of their houses but not at the rate described.
What I found more annoying is that families like Landgraab or Alto (the so called big families) leave their villas pretty fast. (But that has something todo more with these sims not finding jobs)

My big concern in my games so far (with only 1 family disproving this) is that families seem to die after 2 generations, sometimes kids are born 4th or 5th generation but a lot of the times the families just end.
Usually with 2-5 siblings and none of them producing offspring, and if offspring is 'produced' the game does not marry the parent sims, hence making it very difficult to track family connections.

For instance the wife of my current male heir wife is the daughter of the son of the brother of my male heirs grandmother (or something like that)

yeah found out as well that I didn't have that specific bug, but I hate that I have to chain romantic interactions even between newly weds to try for baby

Well I got the same problem the daughter of my founding sim can't go steady with her love intrest.
I have tried the mod and fixall but it doesn't seem to help.

I send a PM to Pescado with my save but i'm posting it here as well
http://www.megaupload.com/?d=YZDP86JZ