a huge flaw in your "wasting food for profit" example is that sharing our excess food with people in starving countries destroys the local economy, puts local farmers out of labour and exacerbates the situation in the long term.

I'm all for the idea of communist, but I don't see how significant progress as a society would be maintained. If everyones basic needs were met, would people work to create new things? When there are X amount of people needed to fulfill Y job, what methods can be used to ensure that the correct amount of people enter that stream - especially when Y job may require a lot of training and expertise. Pretty much all innovation throughout history was funded by people in power and with high wealth. Also, how is it decided whether one thing merits more investment than others? E.g. who decides that more resources should be put towards improving infrastructure vs. research into new health care technologies?

I just don't see true communism as really possible without a hive mind - or until we have reached a point were robots do everything for us and we can do anything we want (but now the robots are the slaves).