As a general rule more protein is better, so if you have option of 16% or 18% I'd go with 18%. You may still need to supplement calcium even with layer, as every individual bird has their own needs (however you may find it sufficient to simply offer eggshells instead of oyster).
If you intend to continue with S&P whole grain mash feed (layer or grower) it's best to ferment it to ensure the birds can't pick out specific grains, and that they eat all the powdery fines that contain the vitamins, minerals and added protein.
As far as the runny eggs, dunno why, but a lot of people seem to be nervous to eat their own produced food even though they know it's going to be fresher and they know what went into producing it. Calling my yolks runny is generous at time, sometimes I barely cook the whites and the yolks are still cool in center - however I've never gotten sick eating my own eggs that way.