There are a number of Vigilante Talents that allow the replacement of a feat if you already have it such as
Shield of Blades (Ex): ... He gains Power Attack as a bonus feat. If he already has the Power Attack feat, he can immediately swap it for another feat for which he qualified at the level he chose Power Attack.
Does this allow you to pick any new feat regardless of the source of the original feat, or would you be required to abide by whatever restrictions were in place when you picked up power attack?
(Eg. A combat feat if it was a fighter bonus combat feat, or from the Gendarme Cavalier list of bonus feats if it was from there)I assume the former, otherwise replacing single feats that weren't chosen from a list is a bit at odds with how you'd treat other feats that were.
(Such as a Warpriest's Weapon Focus in the case of Signature Weapon)
Has to be something he could have picked at the time instead.
So if it's a lv1 fighter feat then you're limited to feats a lv1 fighter could have taken.
For the WP case he gets his WF back and can put the WF into a different weapon.
Yep, your weapon focus feat gets refunded and replaced by the vigilante version but since it was from the warpriest "get a weapon focus" then you just get an second one instead. It doesn't overwrite the rules of the feat it's replacing.
Okay, so what happens if I take the Warpriest archetype that gives you Improved Shield Bash instead, and pick the Vigilante Talent Shield of Fury?
You are out a feat, happens
You are out a feat, happens
Is there any additional text you're basing this on, or is that just your interpretation of the phrase "feat he qualified for at the level he chose x"?
(I don't want to come off as terse or argumentative, I'm just trying to see if I've missed a line of text somewhere or there's an FAQ/ruling on how this sort of thing works. To my mind there's a difference between what they wrote and text along the lines of "feat he could have chosen instead at the level he chose x" that means that people that pick up a feat from a class feature without being given an option aren't disadvantaged by then taking the Vigilante talent.)