I've speed read my way to catch up from early June in this discussion so forgive me if I rehash anything that's been discussed.
As to what's best for Kizer I can only say that my vast experience in watching Browns quarterbacks fail shows me one thing, and that's that there is no single tried and true formula to develop a quarterback. Whichever way you try it it can succeed or fail and with the Browns it has pretty much been the latter since Bernie left.
A few comments on what I've read here. For one I'm surprised to learn that Kessler is one concussion away from being brain dead. I seriously doubt Kessler has actually had a third as many concussions as Tom Brady or Aaron Rogers, based on nothing but opportunity potential. Is Kessler's skull particularly thin compared to them and every other veteran QB in the league? I'm one of apparently the few people who thinks Kessler could be very solid especially to start the season. Kessler does know how to go through his reads and he gets rid of the ball pretty quickly when the center of the OLine isn't allowing a jail break. So put me down as advocating for Kessler to at least start out the season as #1 unless Kizer blows his doors off.
I would be delighted if Kizer could actually win the starting job in his rookie year out of training camp and although I've always been a proponent of the Keys-ian line of thinking that you give rookies a red shirt season if possible, I think there are a lot of factors that would cause me to be fine with throwing Kizer into the fire if Hugh thinks he can handle it.
I think the success that guys like Russell Wilson, Dak Prescott, even to some degree Wentz have shown shows that it's not completely insane to throw a rookie into the fire IF there is a solid offensive line and running game, and especially if the defense can keep scores on the low side relieving pressure on the offense. If the Browns truly think they've taken steps forward with the OLine, running game and the defense then that gives them a lot more breathing room to give Kizer reps sooner rather than later.
I think the supposedly rich QB draft next year and our potentially strong draft position kind of forces our hand in testing out Kizer whether we like it or not. I really think we need to gauge Kizer under live fire for a significant number of games this season regardless of whatever else happens because if we did hit the jackpot with him we really really need to know it before the next draft.
So based on those things I think we absolutely have to give Kizer all the reps for at least the second half of the season.
As for Osweiler? I haven't seen or heard a whole lot about him since we got him. I thought he was worth a flier coming out of college but I did watch him completely suck in some of his starts at Denver and AZ. For me he'd really have to stand out in a very clear, cut and dried fashion to win the starter reps.