CJC - Airline from shore to diffuser does not have to be weighted to bottom, but most people add weights to keep it on the bottom and away from swimmers, boaters and anglers. Lots of things that sink have been used to weight down the airline. Most important point is to NEVER kink the airline; spread the weight out along the length of the weight on the hose instead of in one small spot. Not kinking the hose is much easier said than done for some people, depending.
Compressor can be direct wired or a grounded wall plug can be installed, most use wall plug.
Consider coiling your hose on a wire rack and attaching it to a small car tire. Tire needs a few holes in upper sidewall so it will readily sink. Email me for pictures.
