Refractometer purchase was a great call. It measured my tap water at 1.000 and my tank water at 1.030 so salinity is definitely off.
Once your salinity is in order, and the water is heated all the rock can go in at once. The skimmer isn't really needed untill after you're cycled, you can run it now though to get it through any break in period and start playing with dialing it in.