Is it safe to delete the premade sims?

It's not safe to delete them, but you can annihilate them with NRaas Master Controller. That will remove the sim, and their data that is programmed into the world.

Thank you.

Hmmm... If you mean delete them from the town, I've done this many times and replaced them with all new Sims (or sometmes I just edit the characters and their names). I never had any problems. I do make sure to balance out the age/gender of the replacements though.

I delete game-generated sims regularly when I'm writing a story, just by doing the Object - Delete It cheat. Nothing worse than setting up a meaningful scene and having some paparazzi appear just when I'm about to take the screen shot! I also empty towns regularly as well.

The problem with deleting a sim using Object Delete is that you get rid of their physical appearance but the sim is still in the game. You just can't do anything with it.

You can remove residential sims (sims living in houses) by going into Edit Town, evicting them to the clipboard and then deleting them from the clipboard.
Do NOT evict them to the clipboard and go back into your game without deleting them. If you do this, they will just be added to the homeless pool in your game.
There is no safe way to delete homeless sims from your game without using a mod such as Master Controller.

I've never had any trouble deleting premade sims from the game. It should work just fine if you do it the way @wendyyi1 mentions. Although I've never had any problems deleting homeless sims without a mod either. I've always just used cheats to right click and delete them.

https://www.youtube.com/watch?v=3-Wxx4LE1sU

@ZeeGee , I love your video! Such a great idea to show how sims are deleted using Morgana Wolffe deleting Jamie Jolina as an example, and it is so well made!

Reset Sim doesn't delete them. What did I miss?