As for heal potions, like cure critical wounds potions, they are not canon. Neither are the air walk, restoration, or tongues spells (to name a few clerical spells) available in potion form.
While we're at it...how about wands that have spells higher than 4th level? Maybe limiting the number of spells available per wand (something like 200 spell levels total so 40 fifth level spells, 33 sixth level spells, etc.)