Bard's Possible Abuse?
My first thought was how fun of a support he looked, one I might actualy play. His mechanics looked well thought out too, except a few small parts. A well meaning Bard could be a great asset to his team, but a malicious troll could be a great harm. The ult could be used to stop team mates from getting kills and letting enemies get away, not to mention freezing team mates who are trying to escape so the enemy can catch up. Also, the tunnel can easily be used to give the enemy acesss to otherwise defended areas like the base, or set it up to give them easy tanks.
He looks great in the right hands but could be EXTREMLY annoying and harmful to his team when played by a troll.