You must get to Level 30 as a basic tank, which means no choosing Twin, Sniper, Machine Gun, or Flank Guard until you are at Level 30, then pick the Smasher option.
In a bladder-tank, you can only "read" the pressure TANK residual with the water off and the tank empty of water, leaving only the air-pressure in the top portion. If...
I don't think it matters whether you fight Bowser before getting all the stars or not. As long as you have 120 stars when you defeat him, you'll get Luigi.
Unlike a balloon, which has a very slight pressure difference from your lungs, a helium tank is under high pressure. If you inhale directly from a tank, you're forcing a...