I can agree with this, however I would add rational greed to other as well, each person might be motivated by greed in some way, shape, or form but if you have enough rational thought to see when your greed is being harmful instead of helpful. That line seems to be crossed too easily by too many people

Yes there are finite resources, but there are still more than enough finite resources for absolutely everyone to have an abundance of them, there's enough food, oil, shelter and luxuries that each person could live comfortably and without worry. However like you said, human greed is probably the worst thing that can happen in society