I think that the ID4R prediction is too optimistic. Given that the (weak) Thursday previews were close to 1/4 of Friday's take, I don't see it increasing 25% over Friday proper today.
For Dory, it looks like you just took Toy Story 3's Saturday bump and subtracted a couple percent from it to match Dory's slightly lower Friday bump. Seems reasonable, though I could see Saturday a bit higher. Your prediction would lead to the $74-75M opening that a lot of places are expecting.
The Shallows would need a bit over 20% bump over Friday to get to your Saturday number. I'm not sure how WOM will effect its box office this weekend, but I could see your guess being close.