Incl fumbles-lost that's basically a 1:2 TD to TO ratio. That is unplayable at nearly every level of football. It's nearly impossible to win P4 games with that production from your QB. Good teams will certainly make you pay even if your defense isn't playing at a phenomenal level.
GBo hasn't played in a while, but he has historical stats that won't lose you games. He's a 60% career passer and gets you 2:1 TD to TO ratio. On top of that, he rarely gets sacked and will help a fledgling run-game with his ability as a dual-threat QB. Will GBo win you games as a QB? Maybe/maybe not, but I don't think he'll lose you many games either.
IMO Retzy is a risk not worth the reward. He's a practice QB who has enamored ARod with his offseason production and efficiency, however, that production just isn't playing out on gameday. Some guys just aren't gamers for whatever reason and Retzy is repeatedly telling you the kind of QB he is and isn't. It's now incumbent upon Arod to believe him and act accordingly.
If GBo is healthy I believe he's proven to be your best option to win football games with this BYU team. A team with a Defense that may not need the QB to win you games, but rather manage an offense to W's.