ABT that's really kind of you, glad it helps, even if only a little. i am probably the last person really to give advice, but i just tried to stand in your shoes and describe what i would do in your place. Mind you in years gone by i would have asked DH to do it, and then i would have stood beside him listening to his every word and he would have not done it the way i thought he should and he wouldn't have parried the rubbish the way i felt it needed doing. I would have been busily pencilling words on a piece of paper with suggestions to put in front of him of how to deal with the answers he was getting, and he would not have been able to cope with reading it and listening at the same time and the whole thing would have become bizarre (and quite unintentionally funny, looking back on it!)
in the end i would have felt even more frustrated with the whole situation and DH would have felt unhappy cos he'd not helped me, or so he thought, so he'd get mad with me afterwards in the inevitable debriefing and then say, 'well, next time YOU do it' and then we would be at loggerheads for an hour or two and all cos of my dad, which of course would be just what my dad wanted all along!
So i reckon, use all your excellent research on Miller, turn yourself into a calm counsellor and just see your dad as an elderly guy who is probably not a very happy person (how could he be having treated you as he did) and who is trying to find his way through life like we all are. You are in control of your life now and you ARE a happy person cos you've discovered enlightenment and what it means. Imagine DD trotting off to her lovely school, but if he gets silly about stuff, end it, as suggested in last post, and know that she will be happy at whatever school, cos she's got you and DH and love, and that's all that counts.
DS2 went to the best private school in town, and he had love at home, apart from DS1 who gave him hell part of the time and was lovely part of the time, very hard to deal with when people change a lot, you never know if you can trust them but you so want to be their pal when they are nice. they both got a good education but they didn't enjoy the school at all and scraping the money up in later years to keep him and DS1 there maybe curtailed other things we would like to have done with them (going away for more holidays for instance). I think both DSs felt this financial difference, as they made the inevitable comparisons with their peers whose dads drove supposedly better cars and wined and dined the Head etc (not that we'd have wanted to do that even if we'd been millionaires! :) ) So just be sure if you start down the private education route, you can comfortably carry on without dad's support if you have to.
(Don't mean to sound bossy :) ) P x