The Advanced Races Guide is primarily about introducing new races and providing rules for creating other races, but I thought I'd take this opportunity to ask for things on the classes side of character building.
1.) While other classes have additional options for a favored class bonus (depending on the race, of course) thanks to the Advanced Player's Guide, absolutely no race has a alternative favored class option for the Magus class. Not the seven standard races out of the Core Rulebook nor any of the other races from the Bestiaries. If the ARG wasn't going to include this before, I'd like to ask that it does now.
2.) Speaking of races besides the core seven, if they weren't going to gain alternative favored class options before, can we ask that they get them now? A tiefling witch can only pick between an extra hit point or a skill point. Same with an aasimar cleric. Same with a dhampyr rogue or a changeling bard.
3.) The ARG will include rules for making playable Large-size races, not to mention Large-size Quadrupedal races. However, the Cavalier/Samurai class presents a unique problem for Large-size creatures (Quadrupedal or not). With the exception of a single archetype (the Musketeer, which is not necessarily going to be allowed depending on the group's attitude towards firearms), every Cavalier/Samurai has to have a mount.
But exactly how many creatures are there that are suitable for a Large-size creature to ride (let alone a Quadrupedal Large-size creature), especially at first level?
So I propose an alternative set of class features be introduced for the Cavalier/Samurai. Ideally, they should replace/modify the mount feature as well as anything else dependent on being mounted (such as mighty charge and supreme charge), and this alternative should be worded to be interchangeable with any of the archetypes, even ones that modify only some of the offending mount-related class features.
I'd also like to be clear that I'm not advocating a Large-size-only fix. There are those of us who play Medium-size characters who would also like an alternative to the Cavalier/Samurai's mount. So if this change is implemented, please let it be "all races available".