Can Testing Cheats really damage your game?

I don't know about the sims medieval game. I only know about sims 3. It's okay to turn on the cheat code and use it, but you need to turn it off right away after using it. Never save with a cheat code active. That is what messes up your game big time in Sims 3. For example, I use MOO to crowd objects together in my game. If I turn it on and move a lot a stuff, anything that the objects I'm moving have touched... might show solid for a window or door and you have grab them and let go again. The main problem is that the floor tile can disappear on the floor below or above. So you end up having to move everything off those tiles and replacing the tile above and below. For CFE, you'll often get extra floating tiles that you don't notice until later. Then you have sledge hammer them from either above or below (floor tile versus ceiling tile). Of course, CFE can really mess up elevation inside a house, so you really just turn it on and do what you need to do. Then you turn it right back off.

I don't know about what it might do for static needs. I do use resetsim to send stuck sims home and then they'll pop out of bed in the middle of the night and I have to tell them to go back to sleep.

Some cheats are probably less harmful than others; but for the most part, you should turn the code on, use it, and then turn it right back off.

I've played TSM with testingcheats on for about 460 hours. I can't say I've noticed anything buggy (except the known bugs in the game, of course). I use it for maxing out friendships, primarily, because the friend requirements for quests is ridiculous and annoying.

@Sindocat I didn't know we could decorate the forest entrance and town square? Is that a shift-click option in those locations? Always felt those areas were lacking.

Ohh that is nice! Thank you so much! :) Haven't really explored testingcheats that much. This will be fun as soon as I get my PC sorted, and game installed again :D

Ok, that's pretty good news!

I also play with the cheat on. If I could turn it on and off in-game, I would. But like someone else already mentioned, you have to edit a file to turn the testing cheats on.

So far I only had one bugged game where I skipped a few quest goals at the beginning of a quest. But that's about it. An older save worked for me, I always 'save as' when I begin a new quest. So I don't take short cuts in quests anymore. ;)
I mostly use the cheats for decorating purposes, occasionally giving a hero a friend and to teleport my sims when I'm tired of losing time while walking through my kingdom. It's a shame our heroes don't have horses.

@Sindocat What happens to your basecamp at the forest when you start a quest that puts items there? I don't remember the name, but there is at least one quest that places items near the forest entrance.

Ok. I was worried it would mess up those quests but if the lot just resets, then maybe I'll add a few items to that lot. I like the idea of a camp at the edge of the forest. Your camp looks really nice.