I'm sure this has been done and re-done... but my Thri-Kreen is holding a shortsword. He has the multiattack feat. He attacks with his shortsword, then attacks with his natural attacks, three claws and one bite.
+4 sword, +2 claws, +2 bite?
Or would it be +4 sword, +2 claws, -1 bite?
I.e...