TL;DR: Houston had five turnovers and still beat Tulane. BYU's offense will have to put up at least 35 points to win this game, and I just don't see that happening.

35 points happened. Key special teams plays made it possible. I suspect fatigue or lack of practices and playing time was also a factor.

Offense:
BYU only managed 27 points against UTSA's defense. I expect Houston's defense to be just as good, if not better than UTSA. Let's hope Empey's return will boost the OL significantly.
BYU's passing game struggles when opponents play man or try to jam the receivers at the LOS to throw off their timing. I fully expect Houston to exploit that, and mix in a lot of blitzes to keep BYU off balance.
BYU has a good running game when Allgeier is in, but it gets spotty after him. I don't think BYU can use the run game to keep the ball away from Houston. Grimes have never shown he's willing to call a ball control game like that anyway.
A question that needs an answer in this game: Will BYU's TEs be part of the passing game or not? They were a non-factor in the second half of the UTSA game.

Questions answered: Milne responded well when Houston tried to jam him. I. Rex and Wake made key plays in the 4th quarter to sustain drives. As a result, Allgeire did not have to carry the team.
As the game progressed in the 4th quarter Houston appeared to wear down on defense. In the first half the OL was getting stood up on the LOS, by the end BYU was not dominating, but they were opening running lanes and giving Zach more time to go through his progressions. I am not sure if this is because Houston didnt have enough depth, or if their lack of practice/play was impacting them. The coaching staff may have also made some adjustements but I'm not clever enough to see stuff like that.

Defense:
There isn't much to say about Houston's run game. Houston's leading rusher had 57 yards against Tulane and it was not the primary focus of their offense. (157 total split between three RBs) It all comes down to Tune. As poorly as BYU did when bringing pressure against UTSA, I doubt bringing a lot of pressure is in the gameplan this week. If BYU brings pressure, Tune is mobile enough to punish BYU for it. I expect to see a lot of "drop eight" zone coverages and Tune will probably have another 300+ yards passing game because even if the underneath routes are not available, he'll have all day to wait for BYU's zone coverage to break down.
A question that needs an answer in this game: Will BYU's defense be able to make a stand in the redzone and force FGs instead of TDs?

Houston's run game was not a factor. It was all about Tune. When BYU played with three down linemen Tune thrived. When BYU adjusted to a four man front it helped, but it still wasn't enough. (3rd quarter) It was only after BYU started to mix blitzes and stunts with the four man front were they finally pressuring Tune enough to get him out of sync. At times in the 4th quarter Houston's OL seemed legitimately confused by BYU's defense.
Like the defense, Houston's offense seemed gassed at the end. Receiver routes were not as crisp and Tune was not throwing as well either.
The question answered: It was a big deal that BYU kept Houston out of the endzone on that first drive.

Special Teams:
Houston has speed. BYU probably won't have Oldroyd, and if they do he probably won't be 100%.

Houton's 13 yard shank was a huge special teams gaffe that gave BYU a short field. The onside kick by BYU did not net any points on the scoreboard but it seemed to be an important shift in momentum. That was a straight up win for BYU on special teams.

Weather:
Probably a non-factor, expected to be mostly cloudy, 69 degrees, with possible scatter rain. 

The only way the weather could have been better is if they played at Lavell Edwards Stadium. 🙂

Other factors:
First road game for BYU (with fans.)
BYU has ball control issues in the UTSA game. Was that a fluke?

BYU fans represented! BYU had no interceptions (an amazing streak) and the UTSA game appears to have been a fluke.

Final thoughts of the game: The coaching and play was about what I expected until the 4th quarter. Kudos to the coaching staff for the adjustments they made.