The pressure test is NOT a law or insurance requirement. They just try to get you to agree to it so they can charge you or lock you in to one supplier.
Had one propane supplier out here try that a few years ago. HE went out of business in about two years. Few where buying his propane.
As far as owning your own tanks. I own all my fuel tanks, diesel, gas, and propane. You will save enough in being able to shop around to pay for the tank shortly.