in 80/20 jet fuel what is 80 and what is 20  is it 80 meth and 20 nitro???

C'mon, Bob, it's in the Rule Book! CL Speed, paragraph 7. 

Not to me.  It's not like "we" fly a hundred flights away from a contest environment.  Cost of "jet fuel" is the least of my concerns.

Let's say nitro from the hot rod shop is $50 per gallon and methanol is $10. That's only $18.00 per gallon for 80/20 jet fuel. That's actually cheaper than a lot of glow fuels on the market today. In the overall scheme of things, jet fliers aren't worried about the cost of fuel.

Wise beyond your years!

why is it that flyers that don't even fly the event are always ready to make it better?

Flying Jets are a big hoot...

Is gas harder to use? Which fuel makes the least noise and is it a big difference?

Not really. A pulse jet will run just about anything that will burn. The biggest trouble is figuring out the correct fuel air ratio. That's an assumption based upon the tube and valve geometry will "ring" properly. All the fuels will make a bucket ton of noise. That's the whole point... Running jets is a manly kind of thing involving fire, noise and danger.