Jared, I wish you luck, but I'm afraid you may be wasting your time. To JWs who at present have no doubts or issues with the WTS, they just aren't going to listen to you. I think you can present your case better by living a good, decent life, being happy(happiness by non- and ex- JWs just boggles their minds). Keep your eyes open for when your dad may question something the WTS prints or if an elder or CO irk him over some pharisiacal(?) point. If you can crack open a doubt when you see it, you'll get much further than beating him over the head with stuff he isn't going to listen to anyway.
If you do debate with your dad, whatever subject you decide on, stick to that one subject. Don't let him jump subjects on you. God, they love doing that. They get stuck so they jump to another subject. Become an expert on your subject.. Inside out over under sideways down, know everything there is to know about that subject. Know the WTS stance in addition to what ever position you take on it. A lot of times JWs don't even know what they believe.
If I was going to argue with a JW, I would argue the issue about 607bce being the destruction of Jersualem. If you prove 607 wrong, then the whole belief system comes crashing down. Without 607, the end times prophecy of 2520 years doesn't end in 1914. That in turn means 1914 is wrong. If 1914 is wrong, it's all wrong. You don't have to prove any other date right, you just have to prove 607 wrong. This one isn't as simple as saying the Bible doesn't support not celebrating birthdays, but it carries much more weight. I mean birthdays...who cares? This is about your salvation, arguing about birthdays or can I have a beard is nothing compared to false prophecy and deception.