Congrats on the new arrival!
My VF3K was only missing the spring handles for the two doors, but the dealer made good and got me replacements.
I wouldn't fire the boiler without water in it, you don't know what kind of stresses you will place on the weldments when the inner walls heat up much faster/hotter than the outer walls, even on a low fire. Those 8 schedule 80 water pipes will expand and push on the side walls of the boiler and put undue stress on the joints.
Your aquastat is the Johnson controls A350 with the knob on it, the Y350 is the power supply and the S350 is your limit control to turn on the dump valve when the water gets too hot. The S350 is set to 30 degreees higher than the water temp.