Those actions are evil no matter what the era. Did Lee commit those actions, I don't know. I've heard other stories that contradict that narrative of him.
From what I've heard of him and from people of that era, they all considered him a great general and a great man. So do we need a statue of him? I understand that's debatable today, but way back then, people thought that we needed to have a statue of him. And I think there's good reason to still have it today. And I think it would be a shame to take it down.