> There's a lot of arguments going on between different "people" in my mind quite often, most of the time actually, each "telling me their opinion". Which I know is simply me imagining how they might think of something.

This is called internal family systems and it's super useful in therapy. It can be fun to give them names, likenesses and personalties too. But the value is as you say helping you identify competing motivations, where an emotional reaction might be coming from, externalize them (mindfulness for cheaters), and make decisions where there are trade-offs.

I've kept my IFS since I was a tween and it's sweet to look back and see how much they've all grown and matured.