No it won't. You need to use petroleum to grow and produce ethanol. How many ethanol plants use ethanol for their own fuel fuel? How many farmers are fueling their equipment with ethanol?
There wouldn’t be biofuels if there was no breakeven point, so YES, biofuels will work. Some work better than others, obviously.
As of now biofuels don’t amount to much in the way of total use of production, and are not causing food shortages. The price of crude is driving up prices, and there is rising demand for food (as usual), along with some drought here and there.
Acreage under cultivation goes up and down, but due to improvements in yield (some of which is due to petrochemical use, including mechanization) acreage per capita has been on a slow decline in this country.