| mstieler |
I think that pretty much none of these items work.
Your line of logic is way too convoluted for my tastes. I think the simple interpretation of "These special statistics can be adjusted only by penalties, circumstance bonuses, and conditional bonuses." is that they can only be adjusted by penalties, circumstance bonuses and conditional bonuses. The Potency Rune doesn't give you them, it doesn't work. Done.
Not sure if you were replying on my initial post or to Dante's; my instances all involve things that don't affect the special statistics granted by the Form spells. I am 100% on board with nothing being able to adjust your AC, TAC, ACP, Speed, attack bonuses, damage bonuses, or additional damage dice; possibly even senses. Any Athletics (or Acrobatics or other skill bonuses granted by some of the other Form spells) would not be adjusted by magic items, though if those magic items made your personal bonus higher, you could use that as stated in the spell.
The Form spells don't modify saves. Most form spells don't modify resistances or weaknesses (Pest form having Weakness to Physical, Fire & Water forms from Elemental Form having resistances & weaknesses). Gorget of the Primal Roar seems like it's meant to be used in form, which sounds like it would be a case of "specific trumps general".
I just feel there's more clarification that could be made as to what all can be granted. Looking at Druid's Vestments, it appears that is the intended way to boost AC, Attack Bonuses, and Skill bonuses for the Form spells, but nothing in that is said about saves, speed, or anything else. There appears to be no way to increase the damage dice or damage bonuses of the attacks past their highest Heighten version (6th for Aerial, 5th for Animal, 7th for Dinosaur, 8th for Dragon which doesn't even double the damage dice, 7th for Elemental, 5th for Insect, and 4th for Pest).