I guess the Fair Source License should fit in there:

https://fair.io/#license

This is basically "you're free to use the application and the source unless you're a company where 25 people or more will be using/modifying this software". Mind you, I see an issue with this where proving that the number of people are actually using the software is difficult. I'd prefer a version where it's just the number of people in the organisation in total.

I don't think I could use that software as a student. Even if I was considered independent of the school (which is unclear), my professor would not be, so I would not be able to use software under that license in a project for credit.

Here's one: https://creativecommons.org/licenses/by-nc/3.0/

Aren’t Creaive Commons licenses not suitable for code? Can’t find a reference but they seemed pretty clear about that.

Correct, Creative Commons recommends using alternate licenses for code. See “Can I apply a Creative Commons license to software?”, https://creativecommons.org/faq/#can-i-apply-a-creative-comm...

Creative Commons licenses are good for documentation and manuals.

You are correct. And yet I've found multiple cases in which they're used for code.