I like the idea, but maybe something with a different name...like a Dark Cypher, a Grey Wizard, or an Umbral Mage would be better. Necros are just so common in other games, it's hard to think of the job without immediately comparing it to multiple other titles. I like that FF14 does it's own thing (mostly) with job design.

But, in terms of the design options you've mentioned I also don't think SE would be very keen on making a job with such a vibrant identity. After what they did to our jobs in 5.0 I honestly think they hate healing jobs and are incapable of making anything but boring, stripped down healing professions.