If you really want to use the Chara/big body adjustment comparison:
http://espn.go.com/nhl/player/stats/_/id/145/zdeno-chara
Chara came to the league when he was 20, it wasn't until his 5th season (25) that he really had his breakout year and he continually progressed as he filled in and adjusted to his body.
Myers is a better skater than Chara is currently. The issue is he's trying to do everything and he simply isn't ready yet. I'm going to be patient with Myers. Locking him up long term is a great idea. It's overpayment now, but the idea is we want to win cup(s). You do that by locking up your talent. Myers has showing the commitment off ice and work ethic you need. It. just. takes. time.
http://espn.go.com/nhl/player/stats/_/id/2278/shea-weber is another example. Not until he was 24 was he able to log big minutes and be a #1.
Jettisoning a 22 year old, 6'8'' player who has done everything the team has asked of him is stupid. Myers is going to be fine. Period. Flipping out because he's strugging a bit is silly. Be patient. This is a transition year not a contending year. We should be a playoff team, but we aren't going to steamroll anyone to the finals. We've got a strong core of 18-23 year old's, led by Myers. Myers, Ennis, Grigerenko, Hodgson, Foligno, Armia, Girgensons. This is our new core. Trading any of them now is stupid.