Is it safe to use EA's own pre-made neighborhoods?

Well, I want to make a definitive save, so whenever I want, I can just grab it from the backup and start a new gameplay. I thought about creating my own empty versions of each neighborhood—downtown, university, etc.—but besides all the work, having to recreate Sims, losing NPCs, secret societies, etc., I kind of took a step back.

So I want to do something simpler. If I create an empty base neighborhood and then add Downtown, Uni, and Bluewater Village from Maxis itself and just edit everything, is that okay? Like, is there no chance of breaking my game?

Are the Sims made by Maxis safe?