I really only consider it cheating when you are doing challenges. If a challenge says, "no cheats" in the rules... then no cheats. If you are free playing, no challenge, just you and your game, it's not really cheats to me. Do whatever you need to do to have fun.
I rarely use cheats, even in my non-challenge games. But that's just because I enjoy the "life" part of life simulator. I enjoy making my sims cook and eat. Or go potty or shower. I enjoy making them manage work (in whatever form I have them earn money) and social or love life. I enjoy them struggling to have a family.
I'll use cheats to make the game more challenging. As another player said, I'll use money cheats to take away their money for everything from taxes, to gambling addictions, to a tornado wiped out their houses (bulldoze lot, take away the cash) and they have to start over and anything in between.