Am I missing something, or is the actual spell "Remove Disease" not on the Paladin's spell list? They have all the others (Paralysis, Curse, Blindness, Deafness, Neutralize Poison) - but no disease.
I would hope the only option for Remove Disease isn't via a Mercy; shouldn't be the case if all the others are still listed. Not having it on the spell list means no scroll use, as well...