Dear Moe -
The grade of an egg is an evaluation of the visuals of the egg - its color, shape, and amount of air. So it's not really any judgement of the quality of the henhouse or the health of the hens. This page is from Canada -Canada Egg Quality
So there could still be a risk of salmonella, both from outside the egg and from a hen that is sick.
I agree with you that there's only so much one could worry about
. I used to eat a lot of raw cookie dough!
I'm so sorry to hear about your poisoning! That sounds really rough!