He's already very good, both going forward and defensively, though he's better with the ball at his feet, because of his great technique. He needs to learn one or two things about defending, but he's actually sound defensively compared to most fullbacks. Maicon has been on a level of his own, but there aren't that many RBs I'd prefer to Van der Wiel.
I don't want him so much perhaps twenty games of him. I personally think he's inconsistent personally. However you watch him a lot more so have a better judgement.
Meh, not necessarily. He's not the most consistent player out there, but that's usually an issue with young players. He'll be one of Europe's finest fullbacks in a few years though, playing for a top team, I have no doubts about that.
I see more Dani Alves in him than Maicon to be honest. Nontheless he is going to be worldclass in like 2 years. The guy made some progression the last years.