cant kick
True, but he generally seems to make good decisions. If there's a team mate in a better position he'll hand it off, but I also think he's a touch hesitant to kick when he should because he knows he's a bad kick. Sometimes a below average kick in to a content is better than holding up the play.
he goes missing in games
I think this is more to do with his role in the team rather than a negative towards him. All reports I read had him being prolific when played in the midfield at Under 18s level.
his goal kicking is mediocre at best
Hard to argue this, but I think it will improve slightly when he's a bit more confident in himself.
im yet to see him really quell an opponent as a tagger or a defensive half forward
Go back and watch the Geelong game on Anzac day last year and have a look at the job he did on Joel Selwood.