Question about Edit Town

@Venitia I think it's an "it depends" kind of thing. If you're talking about adding in lots where none were, I get away with it by only doing one (or maybe two) and then save. I understand this allows the game to rebuild routing between changes. Then, if I want to make more changes like that, I continue with that approach in different play sessions. If you take the approach of only changing one thing and then saving your game in live mode with "save as" (renaming it, of course), you should be able to see if you've done anything that's causing problems and can back up to your previous save. You may not notice a break in routing immediately, so I'd suggest playing for a while in the save before attempting additional changes. I add a lot of new lots this way sometimes and rarely have a problem.

I also think it's better to build on existing lots in a different save of your world and then place them in the save you're playing. If I start doing a lot of building where I'm playing (and I'm guilty of doing that sometimes), my games seem to start "going south" a lot faster than if I don't.

Beyond that, having a lot of large, heavy builds and maybe a lot more spawners can slow things down, but where the breaking point for any individual is going to be depends probably mostly on their computer system and maybe their tolerance level, too.