Microwaved eggs was probably one of the first things that I learned to cook -- I don't know I'd consider it an 'omlette' necessarily -- it was just a bowl, oiled, broke an egg in it, a touch of milk or water, mixed, and then microwaved.
When you're rushing to get out the door in the morning, it's a dead simple breakfast; I was recently out of town, and the place I was getting my breakfast in the morning (a bagel joint) did basically the same thing -- put a laddle of egg into a container, microwaved, put it on the bagel, and you were out the door.
Personally, I'm of the opinion that velvetta melts at a low enough temp that if you're using the pre-sliced stuff, you'd probably be okay just cooking the egg, putting the cheese-food on it, leave it in the microwave (off) for ~30 sec, and it'll have started to melt.
(but then again, I like to know cheese is there ... not be some runny molten filling that runs out when you're eating something, so I don't want it too melted)
Nuts can go rancid. I've also had stale nuts, pecans or peanuts that were exposed to too much humidity. This adversely affects the texture. They need to be fresher than that.
Cashews, however, are in a slightly different boat. See Anacardium occidentale L.
Cashews have a toxin in their shells that resembles poison ivy. When harvested, cashews are roasted in their shells to reduce the toxin and make the shells brittle and easy to remove.
If these cashews were harvested by an amateur this process might have not been done correctly and you may be reacting to the toxin.
Best Answer
As long as the rind is still encasing the cheese, it should be just fine, as Gouda is aged for weeks anyway, and its salt content preserves it.