
Consistency-wise, yes, Chan needs to grow. But artistically, I think you mean "he has room to grow artistically"... he doesn't need to artistically grow in the sense that he doesn't need to keep up artistically, since he is the best of the field artistically. Right now, he's in a class of his own (though the other guys, like Hanyu) have made up ground.
As far as "huge technical issues", I strongly disagree. Skating-wise, he has no flaws (or at least no major flaws). Jumps-wise, his issue isn't technical so much as consistency and maintaining focus -- his technique on every jump (save for his triple axel) and spin is fine.
Hanyu is similar although lately it seems his quad toe is giving him trouble and of course there's his lutz... he's also improved his lip from a e to seemingly no edge call (although if he were any second tier skater I'm sure the tech specialist would call it as a !). His overall skating quality is the biggest thing that's improved, otherwise I'd totally give the nod to Chan this season. I think Hanyu's base difficulty and having closed the PCS gap will keep him ahead of Chan for now.