Id give him 9 games for sure, specially considering guys like Gus and Mesz have been less than average. Reward the kid for working on the aspects he has needed to, and show the other guys that they need to step up if they plan on playing this year.
I think we have something special in this kid, I have been nothing but excited for what he has shown since he was drafted, you can see what he will bring when he gets a bit older, and by the time he is 6'7 220+, dear god this kid will be a wrecking ball. IMO he looks like he could shape up to be a new era Pronger in our own end, with a lesser offensive side. Although his passing has been suburb so far, his shot, and quickness in that area needs a few years.
Sure it won't hurt him to play 9 games here, but if that is the only reason, to reward him for a good camp, I don't think it is enough of a reason to complicate the business side here. His contract will make it tough to get in at/under 50 to start unless you make a move. And that move would likely be a defenceman. Then once his 9 games are up and you return him to Junior you have a hole to fill. Play him through camp and return him just before the regular season starts. That should be a good taste of the NHL for an 18 year old. And it will let his contract slide for a year. His highly touted teammate just got returned from the Leafs. It is time for him to get serious about his season in Rimouski and work on his game at that level.