I would not store eggs for more than a week before setting them in the incubator. You should get better results with eggs that are a week or less in age. Anything older and the quality of the egg can diminish.
As for eating fertilised eggs go ahead and get them down your neck!! They are fine...
My top tip would be to double check your temps and humidity with a seperate, known to be correct thermometer and hygrometer. Often incubators are said to be calibrated but they can be wrong. I find it best to double check just to be on the safe side.
This article is a bible on incubating ~...