Spending a first round pick on an undersized QB from a gimmick offense is a serious reach, but as much as I doubt Manziel will become a good QB, you simply cannot call him a bust yet.
He has a strong enough arm. He shows good accuracy and an ability to throw on the move. There is no doubt he is a good athlete. He is intelligent. He is short, but there are QB's his size who have succeeded. If he sobers up and starts taking the game seriously, there is no doubt he could stick in the league and possibly even become a good player. I doubt it will happen, frankly, but it is possible. As damning as the leaked Patriot scouting report was, anyone who doubts Manziel has ANY chance to succeed should read it. The kid has talent.