even the most cursory back-of-the-envelope shows that there's insufficient arable land to replace any significant fraction of our FF use with EtOH anyway.

That depends on who we are and isn't really a very useful metric anyway. Brazil has replaced over 10% of all liquid fuels  and over 25% of all gasoline use with ethanol(both measures on a on a BTU basis).

Thailand, where I live, is about to do the same thing. This to my mind will replace a significant fraction of our oil consumption.

Ethanol from sugar cane has a respectable EROEI and reduces greenhouse gasses from vehicle use by over 80%.

And how much of their net oxygen producing rain forest had to be burned to have area for the sugar cane? How long will it take until those areas drop in productivity because the minerals are being washed out of the ground?

The only known methods to produce energy from solar radiation with a good EROEI are solar cells and thermal solar plants. Everything else is a waste of time, land and taxpayer dollars.

Don't you think there are infinite other possibilities? How about managed forestry for firewood?  If the EROEI of firewood was bad the woodstove would be a foolish invention no?
And how much of their net oxygen producing rain forest had to be burned to have area for the sugar cane? How long will it take until those areas drop in productivity because the minerals are being washed out of the ground?

The rainforest was burned primary to feed cattle for meat. There is very little linkage between sugar production and rainforest destruction. Brazil has produced sugar and ethanol for thrity years and yields have improved vastly. They are now working on organic production.

The only known methods to produce energy from solar radiation with a good EROEI are solar cells and thermal solar plants. Everything else is a waste of time, land and taxpayer dollars.

That is just a falsehood. Sugar cane to ethanol has an EROEI of 8-10. I advocate solar, but at the moment ethanol makes more sense from economic and energy perspectives. Engineer Poet wrote a whole poast recently about other ways to transform biomass to energy. Read it.