Got my review copies last week; didn't know this thread was about answering q's. Sorry about that! My books are now at home but I still remember some details.
Reapersaurus: Rage is like a mini rage because the Str and Con bonuses are only +2/+2.
Mike Haakstad: Good to see you on the ENBoards, buddy. Special Paladin Mounts start with +2 HD, and gain HD and other abilities pretty quickly (another 2 HD after 3 levels, then every 5 levels, I think).
Riley: Horizon Walker is awesome. It's essentially an explorer who at each level gains power from terrain. Example: you could chose "Forest" as your terrain at first level, and get +4 to Hide checks as well as +1 to-hit and damage on any creatures with "Forest" listed as their environment in the Monster Manual. The Hide bonus applies anywhere, not just when you're in a forest. Reqs are Endurance and Knowledge: Geography.
-z, Amazon guy