I have people in my life (that are not alcoholic) that are more then a little draining to talk to if we talk too often or about certain topics. I have no intention or desire to cut these people from my life. They are my family, I do love them, and all in all there are more pro's then con's to having them in my life. I just need boundaries.
Thinking of one person (my aunt - my mother died years ago so she is my kids' grandma and feels parental towards me just to share the nature of the relationship). So I don't answer the phone if I don't feel like talking. If you only want to talk once a week you can say "OK, Bye Dad, I'll talk to you next Saturday." and then do not answer the phone until next Sat.
If he brings up a topic that you do not want to talk about get off the phone. You don't even really need to state it as a boundary if you don't want to. For the person in my life - if she starts going to a place I do not like I do one of two things. Politely get off the phone, or just do not respond. I don't say one word. I have also learned that she isn't going to change her view on those topics, or her presentation of that view, so *I* need to quit bringing those topics up too. We are close (she is actually the closest person to me in my life) but I can not talk to her about parenting issues or my ex. I want to rip her face off and/or crawl in a hole so I don't go there. We are close and I wish I could have a different experience with her around those topics but I have accepted that I can not. She is also prone to 'Oh, I'm all alone just sitting and looking out the window no one cares blah blah blah' and I listen and sometimes I suggest something but mostly I just don't say anything. When all this was at its worst and I began with the boundaries I also limited our visits because it was harder for me when face to face. I finally learned that I could get up and walk off and/or say something to her in those situations. That works fast because no one wants to be told to knock it off and or get left alone in a room.
A couple things happened. In the short term I controlled things in a way that worked for me without stating my boundary to her at all (because the thought of that exhausts me because she really would not get that) and in the long term the topics that bothered me were less of an issue because whether consciously or not - she knew I'd get off the phone or leave if she started in.
Are things perfect? No. But I'm glad she's part of my life when all is said and done so I'm willing to accept things as they are. From what you post your dad actually seems surprisingly willing to live within your boundaries so it might be worth it to just keep working on your boundaries both on your own and with him.