If you are paying the bills, you are not off base. The issue is though that she is considered an adult. So, there you run into a catch 22.
You are right wanting to see the grades because you cover the tuition and the expenses, etc.
If possible, you may want to set some kind of expectations of her. If this then that.
It is definitely inappropriate to text in class and that many times per day. Unfortunately you won't have a lot of control over that.
You can try to use your influence with her in regard to the things she relies on you to provide for. It is not unrealistic to have a 20 year old earn some money of their own. If they are busy working and having to study, there may not be a lot of time left for the boyfriend. If she does not learn responsibilities at this time in her age, she will not follow your expectations about her choices of a partner either.