1.
http://www.intercepteft.com/calc.html
2. No, though if you are on the stock DME flash your ability to manage ethanol will be modest. The JB cannot adjust the fuel scalars, it just biases and lets the fuel trims adjust to the extent they can. It's fine for E30, but worth noting.
3. People have run ethanol on this platform for half a decade at this point. Not aware of anyone who has had serious issues that could directly be tied back to ethanol usage. The'res no inherent issue with both ethanol and methanol, though if you are spraying methanol as a means of supporting fuel delivery, you owe it to yourself to build a really solid system.