I was in fact happy to learn (not that long ago) that TS4 works a lot better with rotational saves than I expected. For some reason I thought their cash funds would "randomize" while I was gone, that some would switch careers, and relation panel be tossed all over the place. I tested my full 50+ households rotation, and found that most household's cash fluctuated with only around §10, which is practically zero. Nobody switched jobs, there might have been one retired old sim who had gotten a new job, but I'm not sure that happened before or after my awakening.
Relations panel is still a random mess, but it doesn't bother me all that much, I normally focus on relations for just a few households at the time, or I just move them together while working their relation, so it can easily be fixed if some flirt has been cut off the world.
I believe the sims are *not* getting new contacts and new romances while we are away, but that the game randomize them the second you enter the household. It's intentional. I heard relations is one of the bigger problems when it comes to lagging, so that's why they programmed it this way. Adding a new EP will add more to lagging if the pack comes with new relation possibilities/forms. I hardly check the relation panel anymore, besides I hate that we can't sort it by friendship. I'd only be interested in knowing top 5 friendships (and maybe bottom 3, too). Anyone my sim hardly knows is not interesting to me, and when all those are displayed in random order, it gets too messy for my eyes. It feels like the game wants to surprise me with some shocking new contacts, while I rather like to decide those things myself. I'm not impressed with randomness.
I wish EA would explain how misc stuff is calculated, like how is bills and income set up for rotational play? I have my thoughts on it, but I often think I really should do a test run just to verify my assumptions - instead of playing.