OP I think you should trust your gut instinct. There is a reason /there are reasons you chose UT. You articulated a lot and your points all made sense.
While money is not the deciding factor for you, the school you felt was the better fit is also the more economical. You are in a very very fortunate position.
Rice is prestigious and sounds amazing so it is not surprising that you have second thoughts. But you can only attend one school and you seem to have chosen well. Congrats!