@jhadred
yeah archlitches are basically the good version of liches in DnD, but as far as i know that only applies to DnD.
and while some types of healing are considered necromancy, healing in itself is a pretty natural thing.
So unless you are doing something like life drain spells it dont really apply.
we then come to the biggest problem with the question of "what is a necromancer ?"
Necromancers nowdays are predominantly considered necromancers if they use magic that use and controll THE BODY of the dead.
while things like talk with dead and spirit magic are a type of necromancy for sure, you are not considered a necromancer just because you can use one type of necromancy in most cases.
if you were to follow that logic pretty much every barbarian and shaman archetype out there would be a necromancer as a lot of them use spirit / ancestral / totem magic.
while i would consider it a type of necromancy a druid or a shaman who talks to the spirits of nature or the souls of the ancestors are still not necromancers.
alot of cultures have spells and so on that works with the souls of the ancestors, but again... you are not a necromancer just because you know one spell of borderline necromancy.