"I still want to know why Neptune's orbit isn't as far out as Pluto's average orbital distance: "
See: Nice Model. The planets didn't settle down into a primate-pleasing, mathematically-simple arrangement because they're the result of chaotic collapse of an interstellar cloud of gas and dust. Our pre-solar cloud initially collapsed into a very different pattern than is observed today and the planets gradually migrated into the current configuration.
"this would validate Titius-Bode."
No, it wouldn't. Having the solar system set up in the pattern of Titius-Bode would be a single case of Titius-Bode working - a coincidence not repeated elsewhere. Titius-Bode is not repeated in the moon systems of Jupiter, Saturn, Uranus, Neptune, or Pluto, nor in any of the observed extra-solar planetary systems.