Very good OP. Thread was tl;dr most of it but here is my 2 cents.
I saw a couple posts that mentioned teams putting 9 guys in the box to stop McCaffery. Iowa's safeties are very good at coming up in run support without having to stack the box. Stanford hasn't played a team that hits like Iowa does. I can't imagine how sore those boys were after the B1G Championship. That was a fun, old school football game. I expect the Rose Bowl to be similar but with more points scored.
I've stayed up late and watched Stanford a few times. Their offense is fun to watch. I hate watching the Big12/Pac12 because it's more like watching a track meet than a football game, but not Stanford. They line up and play big boy football. Their tight splits on short yardage plays really intrigues me. Hogan reminds me a lot of the Wisky QBs over the years (not Russell). Not flashy, can move the sticks, gets them into the right play, and let the playmakers win the game. Hopefully he can channel his old self and give Iowa the ball a couple of times. Iowa's D will win some battles and Stanford's O will get theirs.
Stanford's defense is were the Rose Bowl is won or lost. A couple of the games I watched, I thought to myself, 'Iowa could run for 350 yards on these guys.' If Iowa can pound the ball with success, Iowa wins by a couple scores. If Stanford's D can nut up and force Iowa to throw it will be a close ball game.
I disagree that Stanford hasn't seen a defense like Iowa's, just looking at statistics I think Washington and Northwestern are at least as good. But that's good for Iowa -- Northwestern stopped Stanford and Washington played pretty well and would have done better if they had any offense. Stanford did screen Washington to death, which stymied Washington's athletic and aggressive front 7.
But I am scared that Iowa will just be able to run the ball at will against Stanford. I don't know how explosive your RBs are. If Stanford can at least prevent big plays and hope for a third down stop or turnover, that will help, even if Stanford is giving up chunks of yards on the ground regularly.
I don't think the only options are Iowa's run game doing well and winning by a couple scores and a close game. There's also a chance that Stanford wins by a few scores -- otherwise the Vegas and computer-projection lines wouldn't have Stanford as a favorite. This is the best offense Iowa will have seen. How Iowa deals with that is a key question. If I had to bet, though, this game ends up something like 28-24.
I would guess that a typical Stanford team (not sure how "typical" the '15 version is) is as much like a B1G team as any in the PAC 12. Probably the only team there that puts such a premium on defense & running the ball.
The Pac-12 is somewhere between the Big 12 and Big Ten in style. There is also a lot of diversity in the Pac-12. You have teams like Oregon that run spread offenses and teams like Utah which is a lot like a Big Ten offense. Stanford is closer to Utah in style, but Stanford's offense is more of a pro-style offense (as is USC's) than a true run-first offense. This year, Stanford in particular isn't run-first. Stanford likes to use lots of formations and checks at the line. You will see everything from the wildcat to five wideouts, to 7 offensive linemen. Some Stanford fans will tell you that the offense is too complicated and David Shaw should stick to what works best, but the offense looks great when you have an experienced QB and everything is clicking.