Yep, the script isn't necessary. There's still a lot to learn about item scripting I suppose.
On the flip side, making OP potions is incredibly simple. I mean, with just a few additions to my earlier Stat file...
new entry "POTION_Rhidian_Healing_Potion"
type "Potion"
using "Potion"
data "Act part" "9"
data "StackId" "AwesomeStuff"
data "ComboCategory" "PotionHealing"
data "Value" "4"
data "Vitality" "5"
data "FireResistance" "100"
data "EarthResistance" "100"
data "WaterResistance" "100"
data "AirResistance" "100"
data "PoisonResistance" "100"
data "Duration" "-1"
Then all of a sudden I have a potion capable of giving a *permanent* boost to all resistances to the tune of 100%. Looking through the other Potion descriptions, it should be easily possible to make OP stat increase potions as well.