The only help I could offer is to look at places that sims and pets can get stuck. Fences and hedges will sometimes trap sims or pets spawning or dislodging from vehicles and poofing right into a hedge. (This happens to me at the science facility in Sunset Valley, for example.) So, I delete fencing and hedges around rabbit holes. I also recommend using nraas's overwatch to help fix errors like that. They also have a mod to help prevent errors from happening. The other thing you can do would be to delete some cache files that grow quite large from normal play. For me, it is the two compositor caches. The simcompositor cache can climb up towards 500,000 and then I need to save my game and quit to delete the file before reloading my game. The compositor cache climbs up to 100,000 when I'm busy CASting items. So, again, I save and quit and delete that cache before reloading. Also, IF you don't use "save as" instead of "save" when you save your game, it can carry over corruption that "save as" avoids as that creates a fresh save rather than overwriting the old.