I read you whole vent, I just want to say sorry that your father seems so disappointing. It really sucks when you need that person to be everything you need and they don't come through, not even close.
I guess on the flipside, it sounds like you have a nice mom, some brother and sisters and you'll be getting a new brother-in-law soon. I only have one brother, wish I had more or sisters or something. We have a small family and I always wish there were more of us.
Anyway, hope your father has some kind of epiphany or someone does an intervention or something. You don't deserve inappropriate behavior like that. It sounds at least like your mother raised you right and you know the difference between decency and indecency. Some people with awful parents just can't help but become awful people. But that's not happened to you, thank God, right?
Take care of yourself, and someday you can move out and when your Dad misses you, maybe that'll be the kick he needs to appreciate and show love to you more.