I have read a lot about how he had very strong convictions but at the same time they drove him to commit crimes against humanity. I also wonder if he knew or was happy about the increasingly tyrannical regime of Castro in Cuba that he played a major role in forming?
It sounds like you're coming at this with a lot of presumptions/prejudices.
Guevara was harsh, but a lot of the worst accusations against him are myths unsupported by evidence. While Communists in Cuba made him into a faultless hero, anti-Communists tried everything they could, including making stuff up, to discredit his memory. Neither version is true.
It is difficult to give you an answer without a full dissertation on the key moments of his life. I strongly suggest reading Jon Lee Anderson's Che Guevara: A Revolutionary Life. It is the most serious thing written about him to date.