
LoneKnave |
You can't flurry and spellcombat at the same time. Not only are they their own, non-combinable actions, flurry takes up your off-hand attack (although the extra attack can be made with the same hand).
That said, you don't need spellstrike to deliver touch attacks with unarmed strikes anyway (it only gives you a free attack on the first cast).
There are some nice combos you can pull off though.

lemeres |

Plus, how is he going to get the natural weapons into his flurry of blows? They are normally not allowed when you do that.
Admittedly, there is feral combat training, but that just basically makes the natural weapons into monk weapons, and overall it would be little different from an unarmed strike. Well, you could get 'only one natural attack' bonus, or the natural attack might have a useful ability like poison or grab. Otherwise, it is kind of a waste, and you only take FCT to get unarmed related stuff applied to a natural attack.

Arachnofiend |

I think he'd be better suited just ignoring unarmed strikes and going full natural attacks. A Maw Tiefling with a 2 level dip in Ranger has a bite and two claws, which is plenty sufficient. If he can afford a 1 level dip in White-Haired Witch he can use his hair for a fourth (this is essentially what I'm doing for my Tiefling barb build, substituting the Ranger levels for beast totem of course).
Since he's fighting weaponless this way it shouldn't interfere with spellcasting at all.