James Jacobs
Adventurer
Because the rules about natural attacks are different from those in 3.5. Bites, gores and claws are all considered primary attacks (page 302 of the Bestiary).
Correct. And since what makes a natural attack a secondary attack is now the type of attack and not when the attack happens, there's not really a need for a separate "attack" line. If a monster makes a single attack as a standard action, it can choose any one of its available attacks (a claw or a bite or a wing buffet or whatever) and make that one attack. The damage and attack roll don't change.