Lets see how I can judge.
Nothing here is meant as snide remarks, but rather constructive criticisms.
First thing, not too much homing attack, but rather bad use of homing attack.
The Sonic guide has a good description of when and how to use homing attack, so he should work on that. Either way, its a move thats used more as a counter move or punishing move, or as a secondary recovery methodeprimary being SideB and UpB).
His overal issues with Sonic seem to be sloppy gameplay, and predictability.
For one, he should notttt be using dash grabs with Sonic. Shield cancel a run, and then do a shield grab. If he does this corrctly, he will slide during his standing grab animation, giving him an equal or longer ranged grab than his running grab, with muchhhh less end lag. Its also safer because you can powershield attacks and still slide in for the grab.
Were there any shield cancels? I don't think I saw any. Shield cancels and feints are virtually integral to Sonic's gameplay. He needs to ASC(Aerial Spin Charge, Down B release in the air) moar when appropriate, its Sonic's main damager, an easy 18 damage so long as you hold forward on the control stick, and thats not including super easy followups. This attack can be shield cancelled upon landingfor great feints, or you can proceed into a spin dash roll.
Sonic's sideB can also shield cancel before its fully charged. Doing a SideB from a run and shield cancelling it into a grab actually gives sonic the most "range" from grabbing, and seems to powershield moves super easy.
He uses dash attack too much when he has better options. Instead of dash attacking, run in and shield cancel grabs.
More tilts. Link is heavy and a fast faller, dtilt followups are easy, although I'm not sure how easily his nair will break the strings. ftilt is Sonic's longest ranged ground move, so he needs to use it more.
Against link, in general, more shielding/powershielding, and shield cancelled feints.
His spacing seems to lack also. I know its hard to space against such an onslaught of projectiles, but once Sonic is spaced appropriately, using thse projectiles becomes a bad option for link. Sonic can cover tons of ground in the time is takes link to execute many of his attacks.
Theres more, but I think I've covered the basics
