The booster was never intended to go above the Karman line. Calling that a "failure" is ludicrous.

Also, the orbiter was destroyed by its flight termination package triggering, which is the very definition of an intentional action. The reason it triggered was apparently an oxygen leak that led to the upper stage running out of oxidizer just a few seconds short of achieving orbit, which wasn't according to the flight plan, but this was a test flight so the plan was always "see what happens and fix whatever problems come to light" so that's still not exactly a failure. They got farther than they did on IFT-1.

You are perhaps more used to the NASA way of "testing", which is to exhaustively perfect the rocket before it ever launches and then expect everything to go smoothly during a single shakedown flight before payloads start going up with flight #2. That's not how SpaceX does things.

My prediction for 3 is that again at least part of the craft will blow up below the Karman line.

Given that the booster is never going to cross the Karman line (booster separation happens at 64km), and that the intention is to deliberately ditch the booster in the ocean rather than recover it, you've got quite a conservative prediction there. I honestly can't think of any possible way that this wouldn't happen.