By todays standards there were very few nice guys back then. And your assessment of him was right on the mark. We just have to look at him as being a product of the times in which he lived. As an Irish-American I can rave on about Irish Monks getting here well before him....but a few stones and/or scratchings being left and nothing else do not make for a significant contribution. Thus, lets give him his due no matter what revisionists say.
That's simply inaccurate. Columbus was an individual with enormous character flaws -- he was not merely a product of his times. That's one of the reasons he was brought back to Spain in chains. I'm not trying to detract from the significance of his discovery, but he was not a good man by any stretch.
I would add that I think it's beyond clear that the man was a certifiable genius.