“There is no damage, if aluminum corrosion occurs it is probably from the absorbed water.”
One of the major problems with ethanol is that when stored too long moisture accumulates (note: never buy gas from a station that has low inventory turn-over).
Yeah, and probably don’t “fill it up” unless you are planning to use most of it right away.
The station storage tanks are vented to the atmosphere, and they pull in air as the gas gets pumped out. I don’t think they have driers on the inlet vents.
That’s how water gets into your vehicle’s fuel system.