Basically, with wpnmastr, you get +1 AB at every five levels of the class until you take the Epic Superior Weapon Focus feat, after which you gain +1 AB every three levels instead of every five levels. You don't get both, but the AB bonuses do stack. And yes, it works in Layo.
As long as we're nitpicking, you can potentially have 30 PrC levels due to the pre-epic 10 level rule. I'm fairly certain it works like regular weapon focus, where you get a one-time bonus. Only the epic version is different, where it gives an additive bonus every three rounds. So you get +1 pre-epic and another stackable +1 at levels 13+(3).
Read the Descriptions for the Feats... It says exactly how they work, which is why I asked these questions. [lore]Superior Weapon Focus[/lore] States: [INDENT]A Weaponmaster continues to receive this feat for every five levels taken in the class (5th, 10th, 15th, etc.). The effects stack, so for instance, a character with twenty levels of weaponmaster will have a +4 bonus to attack with their weapon of choice. [/INDENT][lore]Epic Superior Weapon Focus[/lore] States: [INDENT]Specifics: The character gains a +1 bonus to all Attack Rolls made with his weapon of choice at 13th level and every 3 levels afterwards. This bonus stacks with the Weapon Master's Superior Weapon Focus feat.[/INDENT] And what 10 level pre epic rule? As far as I know you need only 5 levels in any class taken before level 21, and if your just making a Fighter Weapon master, you can have a 6/34 split, or even a 5/35 split... I'm not asking this for my PC, since I am not taking Any more then 7 WM levels with Tyra. This is just a general question.
You can't take the feats other then by being a Weapon Master. They are not Layo special Feats. They are Native NWN Class feats, so you can't take them if you're not a Weapon Master
Just to be clear, the 10 PrC level rule is an NWN limitation, not a server rule.