checking for cracked head or bad head gasket..

You need another person to crank over the car while you are looking at the spark plug holes to see if any water is coming from there. If you see any signs of water from the plug holes they you need to pull that head and the intake.

From the sounds of it you really need to pull the engine, replace the freeze plugs (since you say you have 1 leaking and the rest will follow very soon) and have the heads checked and regasket the whole engine.