I like SimWardrobe's CustomersLeaveAfterPurchase, it pushes them to leave after they've bought something.
(Available from the link in Bulbizarre's signature in case anyone wants it).

I use Cyjon's version of that mod. It only works for player-owned businesses though, I'm not sure about SimWardrobe's.

I think they could stay on a commlot, but not home business. On a commlot they can use other facilities like food and coffee, which by themselves don't make a profitable business.

I think a good place to patch in a population limit is in the... Populator. It counts the number of items on the lot, but the limit doesn't apply to owned business. The default count is also a bit generous and wrong. Count all lead tiles in world with their master definition community sort non-zero, and function sort not decorative, including disabled that are set for sale. This would also limit populations of graveyards and small square parks.

I think it was one of the ufbottombaggypants files. I can't remember who made it, possibly Rudhira? I've changed a lot of my defaults lately.

Oh my goddd apartment neighbours why are you so LOUD. My sims (families of 5-10) live in a 6x7 room and every 1-2 sim hours they get woken up or distracted etc because the neighbour is too loud. Ugh, I mean I live in a terraced house and can definitely hear my neighbours (especially my 89 yo neighbour who blasts her tv from 6am until 6pm ) but even then... this seems a bit extreme...

You hear apartment neighbors if they use a drill or other power tool on the walls, several rooms away. Seems like today nobody uses a screwdriver anymore when they need to do a few screws without predrilling. And apartments are usually made of concrete where they need to drill a long time.

My neighbor has some kind of rattler device attached to the window or the surrounding wall. He or his pet uses it randomly. It sounds like a noisy wheel or a flap rebounding a dozen times every hit. I imagine anything that is coupled to walls could be heard.

Maybe they had been drinking vodka juice and are dancing on the floor and shouting obscenities. You hear that too.

In the spring you might hear birds that step onto the steel plate that protects the wall under a window, or try to extract something around the wooden frame of a window, and also chirp randomly.

I love making my sims go around to complain to them, the animations are funny! Also a great way to make enemies for MOAR communal space fighting!

Strategic furniture placement can help too (apparently having achair against the wall makes it soundproof in the Simiverse.

Putting up a zillion posters prevents sound from leaking through. I wish it was like that in real life.

Really? I wonder how it is implemented.

The 'noise' can only spawn on blank areas of the walls. I think with moveobjects on you can even pick it up and delete it.

Light fixtures don't seem to block noise though.

That makes sense. I remember reading that things on the wall block out noise, but I'm playing a Test of Time challenge, so I just put candles on the wall and it didn't work.

I swear the "WooHoo in Car" want only ever shows up when there's no car present.

See simler90's Want Check Tree Fixes:
https://modthesims.info/d/626220

That reminds me of the Fallout 3 train hat

How I have to make sims immune to illness in order to use the Sun&Moon chickens since they're cloned from the roaches and still give flu. Frankly I don't know why roaches give flu in the first place, I mean I know bugs CAN carry disease, but it's a bit much if you ask me.

Chickens do carry a lot of diseases, seems realistic to me!

Yes, but considering they've been domesticated for 8,000 years and people have known how to wash their hands to prevent disease for at least a century and a half, it'd take a little more than four or five interactions to catch anything.

Yes, they do, as witness the current bird flu epidemic that's wiping out huge numbers of domestic and wild fowl/birds.