If I've gotten this correct Exotic Mount lets you pick a common mount profile you have access to and add 2 Biest traits. Assuming that is correct:
1) If you take a Kingdom, presumably it uses the highest of either basic attribute. Does it also get attacks even though common mounts only trample?
2) Can you take the Monstrous Beast (Monster 4) trait and completely replace the profile with a Monster profile that gets 4 Monster traits with normal monster attacks? Yes, I understand that it would end up being equipment that's removed if the rider dies.
1) This adds traits from the Kingdoms but does not give you their starting characteristics.
2) Yes.