Do the dead sims that add up have any purpose, or can I delete them without worrying about anything. I don't mean the dead in my town that I once played or care about, I mean the dead from the vacation neighborhoods and whatnot. When I go through the MC menus and click on "dead" there are a lot of sims on there that I don't remember. I think I want to TA all the ones except for those in my actually homeworld.

Adding on to that - let's say I play for several generations and my list of dead sims becomes large, would their being there negatively affect my game? And what is the best way to clean out/restart vacation and university worlds? I go through spurts where I visit them several times, and then don't for a few generations and I don't think I need the game to keep up with them in the meantime.

Are there other sims I need to clear out occasionally? I want the majority of my game resources on my actual neighborhood, and not dragging around all this extra data if it doesn't need it.

The game engine can only simulate one world at a time, It doesn't matter if you have 150 or 15,000 sims living or dead in foreign worlds, nothing is happening to them while active play is in your homeworld. All of the data to be dragged back and forth may cause a minute or so (depends on system resources and hardware) longer on startup times and perhaps seconds added to save times as it gets copied back and forth, but it's not like it's all loading into and unloading out of RAM like the actively simulated world is.

An exception to nothing is happening -- if Traveler is set to Ageless Foreign > False then sims (the ones who are alive) in foreign worlds will increment their ages by one sim day each at midnight local sim time. But what that really does is hold the age up increments pending in the TravelDB file until such time as that sim or their world is simulated again and except maybe for a brief pause at midnight doesn't really add much of anything to the game's overhead. In other words, I cannot say that purging dead sims in Riverview is going to affect active gameplay in Bridgeport at all, in any way.

What I do with worlds that my sims are only going visit on vacations once every few generations is go ahead and let the population age out. If so much time has passed since the world was last simulated that everyone there who is not an occult has surpassed their lifespans, they will die of old age upon arrival and the game is supposed to generate a few households to be their descendants (not the ITF kind, I mean family tree descendants) so that the world is not totally unpopulated. For Uni, I keep Aging Foreign on False as well because I don't want every set of sims I send there to be studying with exactly the same sims as their predecessors. I get my sims there often enough to want to switch out maybe 1/3 to 1/2 of the student population every few semesters or so.

For connected worlds where "my" sims live, none of this should be happening and Ageless Foreign is on True. I don't want to miss my actively played sims' progression and life changing events no matter where they live.

The "best" way to clean out/restart a vacation world or Uni is going to be the one that makes the most sense to the player and what they require. If you just delete the nhd file of that world from your ongoing save, a new one will spawn the next time you travel sims there but it will contain all of the premades wherever they originally were the first time you played it. Instead or from there, one might want to TA the entire local population and use SP Rapid Immigration to put new residents in play. Whichever method interests me more is going to depend on how engaged (or not) I was with the local population the first time and how attached (or not) I might have become to world changes like lot placements and design I made while playing there prior.

Thank you for that thorough explanation. That is all good information for me to consider.