Well, there are five special abilities that are paritularly cool: The bonded mount, the pack, the full mounted attack, pin and tear, and the baying of the pack. Now, both the bonded mount and the pack will be behind the normal types for their level, making them weaker and more vulnerable for their supposed power. Full mounted attack makes sense, though that could be dropped fairly easily. Pin and tear was a specific request, and it is just a normal grapple done through a specific medium (that of a spear for example), with all the attendent penalties and restrictions thereof. Baying of the Pack is mostly kind of cool, but at that level you're mostly hoping to affect the mooks and cronies, probably not the main bad guy.
The other abilities give you the ability to be nice to dogs and to handle them well. Those are nice but not game breaking, and the bonuses to Ride are the same. The bonuses to flanking are rather necessary when the pack will be sub-par, effectively, for their level. And the ability to not be flanked is a nice perk, but he doesn't get it until higher levels.
However, I will agree with stiffer requirements because it is a very nice class.