Answer to question 1. Click below
http://www.popularmechanics.com/hom...-small-engines-from-the-wear-and-tear-of-e10/
Answer to question 2: yes, and it's probably worse here in Cali than most places. I had a gas station put E85 (15% ethanol) fuel in the tank marked as non ethanol and it downright killed a chainsaw in 4 hours of cutting.
Zero question about it...if you have a 2 stroke, buy ethanol free fuel if you can.
I have switched to buying the pre-mix stuff (similar to whats in that article). I use maybe 2 gallons of pre-mix per year....yes its expensive by the quart, but I dont buy it all at once so my wallet "feels" OK about it.
On the other hand, I know for sure its not killing the insides of my equipment. Also nice that I dont actually have to mix anything.
And at the end of the season I buy the ethanol free straight gas to run all my 4 stroke stuff out with.
I feel its a worthy investment since Im just a DIY-er so my stuff should outlast me as long as I take care of it.

