While playing, I thought of something that might be able to get free money from the vanilla game by doing something extremely easy, with no repercussions. Raise the rent of one (or all) of your houses to 50+ for two days. This would work best with larger houses especially, since only one person can move out at a time. This way, you can lower the rent below the rent that you started with to raise appeal levels and make people move in faster. If you repeat that cycle, this exploit will allow you to make a lot of money faster than usual, and without consequence to your city.
*Edit*
I explained this to inform the developer, but I guess you can use it before it might be fixed.