Pantonal vs. atonal is a useless distinction. Pantonality is obviously a class of atonality since all tones simultaneously negate tonality. Schoenberg is however mainly known as a serialist.
A major third a horrible interval? It depends on the scale - tempered or natural or whatever tuning you wish to use.
I agree with John A about how these things are just too subjective to establish as principles. Also about how context is everything. That is what irritated me with Schoenberg's original statement, because he seemed to be removing context. Though perhaps that was not his intention. I also like some of Schoenberg and can easily see why he just had to do something different - after Gurrelieder.
A major third a horrible interval? It depends on the scale - tempered or natural or whatever tuning you wish to use.
I agree with John A about how these things are just too subjective to establish as principles. Also about how context is everything. That is what irritated me with Schoenberg's original statement, because he seemed to be removing context. Though perhaps that was not his intention. I also like some of Schoenberg and can easily see why he just had to do something different - after Gurrelieder.