Nick Claws' melee attack for sting and claws as secondary weapons are at -2 to hit. Should be +21 melee. It would be -5, but it has multiattack and that drops it to -2. If it had improved multiattack feat, the penalty would be negated altogether.
It was the only thing that popped out at me so I thought I'd mention it. Otherwise, it looks pretty good.
Debby