Right, she had a developed greed. And you are very right with that... but that's not the topic at hand. The topic is whether she was just greedy or whether she was actually evil completely.
The only argument I would buy at this point was the Zidane/Kuja "under different circumstances we could have been capable of the same things" discussion. That if the circumstances were different, she would have just been a regular greedy person. But because of her circumstances she was driven to be more than just greedy. She became murderous as well. No matter what inflated her greed, it would not have necessarily made her murderous. A lot of people are extremely greedy and power hungry in this world... but they don't murder for it. That was her that did it, not matter how much her bad traits were exacerbated.
The only argument I would buy at this point was the Zidane/Kuja "under different circumstances we could have been capable of the same things" discussion. That if the circumstances were different, she would have just been a regular greedy person. But because of her circumstances she was driven to be more than just greedy. She became murderous as well. No matter what inflated her greed, it would not have necessarily made her murderous. A lot of people are extremely greedy and power hungry in this world... but they don't murder for it. That was her that did it, not matter how much her bad traits were exacerbated.