So I re-watched the game last night, and I noticed some things about Roh.
First, let me say he is wayyyyyyyyyyyyyyyyyy better at DE than LB. He made some nice plays in the backfield, either tackling the RB himself or driving his man back and closing a hole. He got some nice pressure on the QB, and even drew some holds that weren't called. In particular, he and RVB did a really nice job on some stunts that sprung Roh free up the middle.
The negative I saw though, was a bit interesting. On read-option plays, where they optioned off Roh, he played it a bit odd. Everytime he would do the sideways basketball slide as if to contain the QB, but then late would crash after the RB. This was irregardless of who had the ball. So because of his initial hesitation movement, he was too late to get to the RB if it was handed off, but because he crashed he didn't actually contain the QB either and he ran around him. My best guess is that he was trying to put himself in a position to stop both options, but the effect was that he kept himself from being able to stop either. I know he just moved back to DE, but it happened 5 or 6 times by my estimate, so you'd have hoped he'd learn as the game went on.
Overall, he played great, but this definitely needs to be corrected before Purdue and OSU, who both run some read-option.
As a side note, RVB was a beast out there. He was getting through on pass plays, he was crushing his man backwards on run plays forcing cut backs. I have a hunch that this game will be one of his best ever when the UFR comes out. Huge game.