Not that they've been good, but I think we'd feel a lot better about the defense as a whole if they could catch. Not sure about now, but a week or two ago they were by far worst in the league in dropped INTs, and obviously the Browns game should have been a W. TOs are about the best thing that a defense can do...
Anyway, I think Wiggins will be fine, and has a chance to be really good.
I think Wiggins will be very good at some point but I am concerned about his ability to stay on the field. The dude is so skinny and the bigger receivers will always out muscle him. Hopefully, he can put on some weight and muscle over the next few years without compromising any of his speed.