I'm worried about my girlfriend because of her father.?

I'm 18 years old, a college freshman. My girlfriend of 2 years, Amanda, who is 16 and still in high school, has the worst father imaginable. He is morbidly obese and lazy, and he spends all of his money on his several pack-per-day smoking addiction and 7-liter per day pop addiction, which is killing him swiftly. He is always extremely angry, and does nothing but sit at home watching TV on his couch, screaming at his kids to "get me food, get my pop, take my socks off, empty my CPAP machine" (which keeps him alive while he sleeps). He has no respect for his children and doesn't seem to want Amanda (or her brother) to go anywhere with her life. He doesn't buy them any real food and refuses to willingly pay even the smallest medical-based bills for them. He hates the fact that she has found a steady, loving, and productive relationship with me, since that represents her getting out of the hellhole he's stuck in. His doctor told him that he has to quit smoking or he's going to die, since his emphysema is worsening, but he won't. I'm not a hateful person, but I hate him. I really do. I've never truly hated anyone in my life other than him now. Amanda can't leave until she's 18 years old without screwing up her future drastically, but it's just so hard for her to be stuck there. I've suggested foster care but she says that can't work because the only thing she can realistically do is requesting to go and live with her mother in another state, which she can't do since that means losing a large local scholarship that will allow her to go to college. Emancipation takes lots of time and money, she claims. Apparently she's looked into all of it. She talks to a social worker who says they could bust him for neglect if she wanted, but again, that would send her to her mom, who refuses to move to where Amanda is now because of in-law family-feudal tensions. I would like to talk some more to her grandmother about the whole mess, but she says that will only make matters worse (I'm considering doing it anyway, I'm so pissed off). It's all so ******* tangled. What can be done? What should be done? Thanks! :(