I don't post a lot and am pretty private, so I cannot believe I am going to share this, but something inside me was insisting I tell you my story to help your daughter.
When I was in high school I got straight A's, played three sports, on student counsel, you name it...I was a good girl who did not drink or smoke had good manners and minded my parents. I don't think my parents had one complaint about me until I fell for a guy that I was on the track team with my sophomore year. We were very middle class, not a lot of extras, but my parents were both college educated and I always knew I would go to college. The young man had been tossed around from relative to relative and worked after school at a gas station and my parents said that he would never be "good enough and I deserved better", but in reality, they did not like us dating because he was black and I was white and it was the 80s in rural East Texas. I still remained a good girl, doing everything "right", but I fought them tooth and nail on this one subject and kept seeing him. There was really nothing wrong with him--he was a nice guy from a poor family and didn't have much, but hey, my family wasn't that far ahead--it was really all about race and me embarrasing them in front of their friends because he was black--and I was appalled at the hypocrisy of it. Nothing they said could convince me that he was not right for me. As I look back now, if they had just chilled and let us see each other, it would have disolved on its own, because I really did want to go to college (it was three hours away) and once I got there, I am pretty sure we would have drifted apart and gone our separate ways. Between my sophomore year and end of senior year, they pulled the financial card--(if you live under our roof, you do what we tell you)--beginning with we will take away your car (so I rode my bike until I got a job and bought my own), and ending with we will not pay for you to go to college (so I said fine, I will be with him and I will figure it out).
I was convinced they were wrong about him and that they did not love me enough to trust me to make good decisions, instead they wanted to control me with the purse strings. Even though the guys in the two stories are not the same, and I do share your concerns about the classic signs of an abuser in him, I can see that your daughter might feel the same way I did. You are in a tough situation. Again, I truly feel if my parents had backed off and not put so much pressure on me about dumping him, I probably would have come to the same conclusion much earlier, but the "conditional love" I was getting from them only made me turn to him more.
How did my story end? Well, the summer after I graduated I made up my mind that I could do anything I set my mind to and I loved him, so I would just leave home, live with him, and we would figure out the college thing later. I was sick to death of all my mom's threats and the conditional love thing hurt me to no end--I was a really really good kid and it hurt so much and made me angry that she was willing to throw me away just because I was in love with someone she did not approve of. I left, but that night, thank goodness, he broke up with me. I said he cared about me too much for me to mess up my future and did not want to be responsible for me missing out on college or having to go to the local community college. He gave me no choice and sent me back home. I cried and resisted and cried some more, but today I am so greatful to him for doing that. If he had let me stay with him, I am pretty sure my parents would have made good on their threat to cut me off completely financially, we would have gotten married and my life would have been so different. Not necessarily bad, but very different--no four year college degree, no law degree, no traveling all over the world. I saw him about five years ago and asked him why. He said he knew that we could have gotten married and "made it", but he knew that I could be so much more with the opportunity to go to college that my parents would pay for and that it would be so much easier for me that way.
Although I agree that children should respect the rules of their home and agree with cell phones, cars, etc being taken away as punishment for breaking those rules, I am afraid that your daughter may call your bluff if you take a hard line on not paying for college if she keeps living with him or seeing him. I think you should still pay for her college, to (1) get her away from his house (At least if she is living at the dorm at her college, she's not living with him!) and (2) once she gets to college, it is very likely he will not fit in her life/lifestyle anymore. It is too bad that she is not going further away than 45 minutes. And I totally agree that she needs to see a professional that can be unbiased in explaining to her about domestic violence and how it starts small and escalates and classic signs of an abuser. She may protest that she is not in that type of relationship, but at least maybe the signs will start adding up in her head and she will get out sooner rather than later.
Again, I cannot believe I am posting this, but for some reason a little voice is telling me it may help someone.