I've looked around a bit to see if I can find the answer to this and I've seen a few conflicting opinions.
"As a swift action, a warpriest can expend one use of this ability to cast any one warpriest spell he has prepared with a casting time of 1 round or shorter. When cast in this way, the spell can target only the warpriest, even if it could normally affect other or multiple targets"
The first question is, can a warpriest can use fervor to cast spells like sun metal? It seems that this may have table variation from GM to GM. It depends on if targeting warpriest's weapons count as targeting the warpriest. I've seen arguments both ways but I was wondering if there was some official ruling on this question, or if it will just be left to GM discretion.
As an extension to that first question, if a warpriest can cast spells like sun metal with fervor, could a warpriest cast a targeted spell like Blindness/Deafness or Bestow Curse into their spell storing weapon?
The action would be similar to a magus, fervor swift action cast bestow curse into their own spell storing weapon and then standard action wack someone with it.