Can anyone refute/confirm this about Christopher Columbus?

Well, if that person has evidence backing up their claim, I would be very interested in seeing it.

From what we know, Columbus definitely knew what he was doing, and knew that he was trying to find a route to Asia. He was pretty much running his own show, as you say, because the Crown really only provided financial backing. But he had the express intent of finding Asia, just like he told them.

Columbus may have been to Iceland in 1477. But taking a jaunt from Iceland to Nova Scotia in a fishing boat isn't something that was documented as far as I know, and doesn't seem very realistic.

Columbus did a lot of careful calculations, based off the works of Greek scholars like Ptolemy and Marinus, that led him to believe he had arrived at islands off the coast of China during his first voyage. The geographical premises he began with turned out to be wrong (Eurasia was smaller and the Earth larger than in the texts he referenced). But his calculations made sense otherwise, and he really believed he had found Asia. You can look at his journals for yourself:

http://www.americanjourneys.org/pdf/AJ-062.pdf

At around page 134, he starts some geographical speculation. He concludes he is probably near Cathay, and as the text goes on, figures he must be near certain Chinese cities.

Even after having embarked on a few more voyages to the same area, Columbus died believing he had successfully found a new route to Asia. He was a dedicated man, who had invested a lot of time, energy, and money in this prospect. There's just nothing that I have ever seen to indicate that this was all a ruse. I can't think of any motivation he would have to fake such a quest. This strikes me as a weird conspiracy theory.

As for your comment about Columbus-bashing... Columbus was certainly cruel to the peoples he encountered, which wasn't something he hid, and wasn't something that needed to be hidden during that time. It was pretty well accepted, with only a few scholars beginning to argue that there might be some moral issues (de Las Casas is a great example). But anyone blaming him for "all the injuns that died during colonization" is way off the mark. He himself acted in way we would now find cruel bordering on evil. His voyages certainly opened the way for further colonization. But blaming Columbus for what happened afterward would be disregarding all the other historical factors involved in the complicated process of colonization. Despite what that person implies, I don't think many people actually take such a position. Either way, this has absolutely nothing to do with the navigational issues. And all the evidence indicates that Columbus really wanted to find a route to Asia, and believed that he had accomplished just that.

But like I said, if this person has sources, a lot of people would definitely be interested in seeing them.