So sorry I didn't respond to your questions!
Egg whites: I've beat them, but not to a tremendous degree. Just enough to break them up and barely lighten them up.
It is a very moist yummy cake, but not with the "lava" inside. As for the jello-poking, I've not done it with this cake, as I think it may not go well with the natural lemon flavor. I will say, though, that it is really fun to do a poke cake with a plain vanilla and use a few different jello flavors. It's a rainbow cake, and the kids love to make it!