I don't know if you could consider this a cheat or not, but if you change your tax rate no later than 2 minutes after every hour, aka 12:02, to maximum rates of 20% across the board and then at 12:03 after taxes are paid change it back to your base values of either 10% or lower, your Sims won't care. This is just a quick way to get cash or save your city from being lost or abandoned.
I use it and have zero consequences from my sims. Just make sure that you change it back at the :03 time. Changing it back at :04 is okay, too. Just don't leave it high. If you do use this cheat a lot, then you can lower the tax rate to 0% across the board until :02 comes around again.
i have found that sandbox mode is plenty enough for me to test the limits of SimCity and to get the cheating out of my system. now when i play in regular mode, i know the game well enough to make millions per day in just a few hours of a new city (usually by starting with drilling/mining and trade depots)
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