<human>: Give me the gist of the text in a nutshell

My father called me a lot of names growing up, he didn't like me being around, but we had a similar taste in movies. He was very mean to my mother on a near-daily basis, and put us in several financial problems (secretly put a second mortgage on the house to buy a second motorcycle that was imported, bought land in Florida just to do it when we were just barely above the poverty line, etc.). He also ruined my half-sister's engagement by convincing her that she 'hadn't lived enough' when she had only come back into his life for 3 months. It got so bad that I blew up at him at age 15 on my mom's behalf, forcing him to move out. 

He moved on, got married, and relationships were still pretty strained. i had nothing but awful thoughts about him, and thought very little of him trying to reconnect with me when I was 19. 
Now I've moved across the country, and received a congratulatory message from him, saying he was proud of me and is amazed by my artwork, etc. I plainly thanked him and ignored his next message asking me to friend him on facebook. It's been a year, and now I'm starting to get the feeling that he wasn't *that* bad, and that I should try to be a loving daughter again, even though it never worked when I was younger.

I am absolutely confused about how to handle these emotions and what to do about it. He still has ill feelings towards my mom and my half-sister, but seemed passively loving in that message I received last year. My mom always said 'in his own, fucked up way, he loves you'. I don't know if it's worth trying to let him back in my life, because he always made me feel guilty about wanting him to leave and how 'he's gonna die one day and (I'm) gonna regret how rude (I) was to him'. That guilt is starting to hit me now. I know if I let him back in he will passively aggressively try to hurt me or my mom, or he might possibly try to wheedle money out of me.
<bot>: The bad seems to outweigh the good, but I feel so obligated to forgiving my father and having a relationship with him.