You're telling me you can REACT to low shot and air skull? Because that's just bullshit. If you read he's going to do low shot, you can try and use air skull, keeping in mind that straight laser will beat that.
Air skulls are cool and all, but ground skulls are perfectly fine for zoning. Quan isn't Kitana. He doesn't need to be hopping around doing air skulls to zone effectively.
This talk of Rune being bad without meter is ridiculous. Regular runes are pretty important, not just since they are guaranteed after Bats, Skulls, and MB Runes, which is why people can lock you down with Quan. The guaranteed rune checks condition the opponent.
Also, trading rune with projectiles isn't a bad idea because regular rune on hit is a knockdown, other projectiles aren't. Plus, you can use runes to control running, which makes the opponent start jumping to get in.
Regular rune is fine. I swear, all TYM does is read frame data without thinking about how moves are used.
Also, MB Trance has it's uses. No, It's not something you throw out but it serves a purpose.
Predator's smart discs go away if he blocks or is hit. You can duck or low profile the lasers.
In my opinion, Quan is the best zoner in the game, followed by Predator.