If an Arch-Militant chooses Meele as the Weapon Class for his Weapon Master Special Ability, does this include all Exotic Meele Weapons, or does it only counts for non-Exotic Meele Weapons?

I know the the last Errata clarifies what are Weapon Classes (Melee, Thrown, Pistol, Basic, and Heavy), but points out that Exotic is no Weapon Class. Does this mean Exotic Weapons can never benefit from the Arch-Militant special ability, or only those of the same Class as chosen?

Exotics are a weapon type, more like Las, Plasma, SP, or Bolt.

It's just not really spelled out very well.

If a weapon is in the Ranged section, it is ranged. If it is in the Melee section, it is melee. Like javcs said, Exotic is more of a weapon type than a weapon class. Just because an Eldar Sword is an exotic weapon doesn't make it stop being a sword, or a melee weapon in general. It isn't rocket science.

If an AM chooses Melee as his specialty, all Exotic Melee weapons technically fall under that. Being Exotics however, each requires training to use properly. Without the talent to use a certain Exotic weapon, the AM's unique proficiency bonus would not be enough to cancel out the heavy penalty. He'd still suck at using them, only he'd suck less than everyone else due to having a stronger innate ability for that class of weapons as a whole.

Agreement. A Splinter pistol is still a pistol, it was just designed for those stupid skinny Eldar fingers, so you need extra training to get used to it. Your innate bonus with pistols if you chose pistols would get that bonus.