I really like the Hoard ability. Really liike it.
It's better than Omalesco's Tarrasque thing and i'm probably going to include it on actual dragons in my games, maybe as a feat. I'm not sure what to make of the extra actions thing; you already have a lot of attacks, but then again, you've resisted the oh-so-dull "give it pounce!" response, which i applaude.
Overall, i think it looks pretty playable throughout its lineup, not auto-win powerful, but certainly enough to give a none "i win" caster a run for it's money and stand well against ToB classes.