I will read True 20 before commenting further on its brilliance or error. Back to
Trailblazer:
So just set a DC for, "Beat Mozart at his own game."
That's the same amount of work as giving him a skill bonus. In fact,
it's the same thing.
Absolutely not. Whether the PCs can kill or protect Mozart (CP) has nothing to do with his stats. Mozart is the McGuffin. His guards might need stats; his assassins might need stats. Mozart-- not so much.
He's not the McGuffin. He's just Mozart. Again, I am not taking out my frustrated literary ambitions on the players.
Let's take another nuisance scenario: Given that he's a kid, it's not inconceivable that the player characters might end up his guardians, train him up to be an adventurer, and then - oh, wait, sorry kid, you can't have more skill ranks than your level. I suppose one might say that Mozart just didn't have it in him to be an adventurer, but that doesn't deal with the problem in general.
With respect to the rules serving me, and not the other way around, I am.
I suspect we disagree less about the rules and more about "story". My view on Mozart is that he should be a 0th level character (common man, whatever), with an extraordinary ability in music. That's not particularly different from what you've put across, with the point of difference being in how detailed a 0th level character needs to be. I will confess to taking the side of slavish simulationism and insisting that everything needs hit points.
Including the ground.
Where we appear to differ is in referee style. You seem to be committed to only using Mozart to fulfill some kind of plot purpose. That's not old school, and has very little to do with the rules/referee situation.