The "using position" part is pretty much the idea of this game. There is no strict diverging "romance" route. Some routes are less pushy than others but that is girl specific and cannot be changed. "Humiliation" also is one of the three basic tenets of this so cannot be avoided at all. However, as others have pointed out, the HM does not treat the girls like "sex dolls" nor "slaves". Either way I think this game will not be for you.
I have to slightly disagree on one thing with what others said though, while there is no rape yet in the game, from a technical/legal point of view there probably will be and it can be argued that the requirements for the tag are already met, depending on whether you think "sex" needs penetration or not.
Well, there is one extensive scene where she is forced to orgasm in front of the class (during the "other school visit"). But no major specific HM-Donna interaction so far.