Refusing to acknowledge that they are even his family would require some quite impressive feats of mental gymnastics.
No it's not a feat. Even Rin could do this before Shirou told her that she was being kinda stupid.
Rin failed utterly abysmally at doing it, she spent a large chunk of her time checking that Sakura was OK. And, plus, legally-speaking Sakura
isn't her family. She was adopted out to another family. Rin doesn't need to do any mental gymnastics to deny it, she just has to look at the legal situation, and she failed miserably at even doing
that.
Tokiomi is the "archetypical magus", for the Root he'd shank every member of the Tohsaka in the throat if he had to.
Honestly, that's not the impression I get of him at all. Whilst he's an idiot, he does seem to genuinely care for his children, and I don't see him willingly harming them.
Ignoring and convincing yourself they are wrong is different from doing what you just said.
It is psychological denial. Everything he could learn from them is bad for him to learn, therefor he subconsciously denies it and ignores it.
Also Brah, it is 18 year old Tokiomi, he is not the perfect archetypical magus yet, though he is close. If he was older and had that mindset I would basically be responding the same way as you but how he will be is very slightly different to how he is now.
Well, true, he's not going to like what they have to say, and he might well try to pretend it's not true. When the time comes to decide on giving Sakura away, though, I can't imagine that it wouldn't come to his mind, it's just too much of a co-incidence.
And why harass guy who has not done anything yet?
I'm not harrassing him, I'm just discussing the character. He can play them however he likes, I'm just saying that their interaction would be interesting.