Its against the rules to use mods.

However if you do use mods just don't talk about it or share screenshots on here.

I have seen plenty that share on Reddit.

For the most part most are harmless and actually do a really good job at improving the game, such as improving facial models, hair, and even eyes.

I wouldn't let people scare you off from using them, since there really is no way of someone knowing or Square knowing.