Yeah, you don't know what it is, do you?

you should plug the inputs and outputs of that process into your calculation.

It's powered by the sun and all of the carbon gets pulled out of the atmosphere by nanomachines. As the mass of carbon used for the reaction is only 1/10th the mass of aluminum produced, the mass of the carbon needed for the current world production of aluminum would constitute a fraction of a percent of the world's total current agricultural output. Some additional energy would be needed to carbonize the material, but this fuel could be drawn from the same feedstock, and still amount to a fraction of a percent of the world's agricultural output.

a-c

Not at all. My position is that there is a kind of commenter who thinks themselves "smart" for being able to recite facts about the current world, but can't see when they are applying the facts in ways that show they can't think a few steps ahead from first principles. Instead they rigidly apply the current situation and present it in arguments as if they had actually refuted something. Any escalation is merely due to the level of annoyance from repeatedly missed hints.

The same sort of "logic" you present could be used in the Napoleonic era to "prove" that aluminum smelting would forever be impossible. (And you probably don't recognize the trap inherent in that one, or the other two traps above.)