I like the general idea of this – one of the things I love about The Network is that there’s a set end-date for each of the parts that you play (not the actor, but the parts in the shows they participate in), which lets me play concepts that I would never try for a long-running character, but could be fun for 3-6 months.
Have the freedom of knowing that you’ll only have a character for 9-18 months (I think I would keep things flexible so that if it takes a little longer or a little shorter to tie up all the plotlines Staff wants to tie up, that’s fine), you have a lot more freedom to create the type of character you wouldn’t usually, and you have a lot more freedom to explore stories about loss and failure (because you’re just losing for one generation, you can gain it back next generation).
One concern that you might have is player-created Houses – are you going to let someone else take that House over next generation, or are the players who created it going to feel like they own it now? Are they going to be disappointed that the vision of the next generation doesn’t match their vision for the house?
Something I’ve noticed from The Network is that downtime to arrange the next generation is going to be very important, and you’re going to want something for players to do while you’re sorting it out. The time it takes to disseminate the information on what happened over the last 18 years, approve/alter/deny everyone’s proposals for what their previous characters have been doing and how their new characters grew up, and getting everyone on the same page is not going to be insignificant, and you -need- to have something for folks to RP during that time. Maybe there could be a 1-month break at each time-skip where staff can put up a list of major events over that 18 years and players can do vignettes in the midst of any of them? Show how the previous generation matured and the next generation grew up through the major events of their lives?