There are 2 that are widely known: sun cheat and money cheat. You can cheat this game with Cheat Engine.
No, but there are some hints (for example hint for easy money or faster zen plants' growth).
Nope
The plants aid you in fighting the zombies in different way.
cheat engine don't make real money its fake
999.990
you go to your cheat engine type petsociety cheat engine and you have more money
No, but cheat engine is fake.
you can't
No.
From the zen garden, or during gameplay.
No.