I have two saves where I am playing in a rental lot with either 5 or 6 households (as tenants) and until now, the only bugs are the annoying phone quests all the time when I start playing a household and when I enter a new lot, and the other bug is that the tenants are cooking too much and leave their stuff everywhere which is quite hard when your main character has the neat trait... but aside from that nothing bad has happened and I really hope that won't change.
I don't send them to Tomarang, though because there is nothing really to see (in my opinion). I checked it out once and that's it. But yes, i do have other rental lots in those two saves as well with Sims I barely play, so I think I might have up to ten or twelve rental units per save.
If it interests you; I am not playing with any mods but some CC (self made and downloaded).
