I think the guy could actually make it in top teams, he would perfectly suit Arsenal e.g.. I think his major problem is that he's given a role he's not used to play at. He would be a great ball-winning regista, winning aerial duels in midfield, winning the loose ball and getting possession back and subsequently delivering the ball to players higher up the pitch. I'm pretty sure he would also feel more comfortable if there was a wide player constantly available for him to interact with (he's shown pretty good understanding with Jovetic, Perisic and Ljajic when they were deployed close to K-dog), or an AM he could deliver the ball to.
Instead, he's constantly used as Mezzala, drifting out wide, and as a result he is found alone in midfield too often. Thus he has to attempt riskier moves, since the obvious ones are not available. Our forwards are also not that good in terms of off-the-ball play, thus K-dog cannot cut the opposition defense with a through pass which is one of the main thing a Mezzala should do.
What he should definitely improve on is his first touch. Other than that, I don't see that he's problems are his personal skills. It's the lack of interaction with the rest of the team.