He's a top faceoff guy in the league; plays 20+mins a night on the PP, PK and ES. Has good offenive output, dynamite on the breakaway and shootout and plays one of the most risk-free games I've seen.
No disrespect but you're pretty much wrong on all counts.
The difference between Bozak and a completely average faceoff guy is ~51 faceoff wins a season, or slightly more than 1 extra win every other game. In the last full season, Bozak ranked 31st in faceoff percentage among players with 500+ faceoffs taken. That's not a "top faceoff guy".
Good offensive output? He plays with two point-per-game wingers and hasn't cracked 50 points. In the over 8 hours he's played WITHOUT Kessel, he has 8 points and the Leafs have been outscored 31-16. Over the past 3 seasons, despite playing with Kessel almost exclusively, his even strength point production ranks 185th of 228 forwards. Other forwards who score points at the same rate as Bozak include Torrey Mitchell, Tomas Kopecky, and Rene Bourque. None of those players play with Kessel.
As for his game being risk free... Well, he touches the puck so infrequently and is so uninvolved in the play defensively that it would be very unusual if he was in a position to MAKE risky plays.
Couturier hasn't proven anything yet. Well, he's proven he can play in the NHL. Bozak has played well in the NHL. You can argue if Couturier would be better if he were given legitimate minutes and such, but we don't know that. So, based on actuality, Bozak would have to be the better player.