You should judge a man by HIS times not yours. The rulers in Europe at the time behaved the same way toward their subjects. He could do no more, we shoud expect no more. As far at the milions who died from diseases, this was not germ warefare, it was just being there. (The first case of which I believe was in CT, USA when the colinists gave indians blankets from small pox victims. Few survived the winter.)
500 years from now I hope I am judged by the good I have done and not what is viewed 500 years from now as mistakes I have made.
All in all, he has made a great impact on the world for a guy who was lost.