Alternative, should be on par with Ethanol.

Not sure how to make this just yet...

Not going to do this for now.

You don't need a new fuel, as the furnace don't need it. my opinion

It was more for engines (BC) or generators (IC2) than for furnaces, Nether Coal fills the gap for furnaces, as well as the vast amount of coal generation in the Nether.

As I think about it... it is usefull for minecart. Do you think it would be a good idea of a netherfurnace minecart? it would have a base power if use in the nether, plus a slot in it to keep lava for unlimited propulsion without redstone tracks

hmm, can you post another issue with that? Can think about how that would work and balance things out :)