Are there legit sources from any pathfinder books on:
-- Tieflings as characters (besides bestiary; looking for stats/build options or at least a write up)
-- Guns (APG has bayonets that can be attached to guns or crossbows but no guns)
EDIT:
Also: IF a fighter/wizard takes is trained as an eldritch knight and takes levels in that prestige class do EK levels stack with Wiz levels for familiar advancement?
Tieflings are in the Council Of Thieves Adventure Path. I think it is the first book in the series.
Guns are in the hardback campaign setting... but only a page or two.