I am curious and its a fairly simple question on the face of it but may be a bit to the answer
Is Negative energy in this setting inherently evil, or simply a tool? Is channeling it an inherently corrupting and evil act, or does it depend on context? (Summoning spirits, animating undead vs energy blasts)
Negative energy is just energy from the Negative Energy Plane, it isn't inherently evil, nor is the plane it came from possessing of an evil sentience such as the Abyss (as far as I'm aware.)
It is the antithesis of positive energy, of life, however, so make of it as you will, it's open to character interpretation. Harmful? Yes. Evil? [Shrugs]
Negative energy itself is not inherently evil. It is one of the fundamental forces of creation - meaning it is no more evil than fire or water might be.
That said, most of the applications of negative energy *are* evil. Necromancy itself is an inherently evil act, even if you are not binding spirits to corpses. Negative energy can also be used to disfigure or inflict horrific pain upon a target, often bordering or veering into the territory of torture, which is certainly evil.
The energy itself isn't evil, but the many ways in which it can be used often constitute evil actions.
I'd say that generally (like, as a nice rule of thumb) negative energy and all things related heavily lean evil on EfU.
Necromancy is not an inherently evil act, it's just that it is easily used for evil purposes. It's advertised as "undead school" but that doesn't make 100% the entire school an inherent act of evil in D&D. Fear isn't evil. Negative Energy Burst isn't evil. Poison isn't evil.
They just are.
Animating the dead in necromancy -is- typically considered by many sources and most DM's to be evil. But the entire school is -not- evil.
Similar to how conjuration isn't an evil school just because you can summon demons with it.
For sake of our setting and server - in efu animating the dead is evil. That is absolute certainty in how it is viewed.
Necromancy is arguable and not necessarily bad, but it is up to debate in game and morally whether it's evil inherently. There have been several characters who have argued it, and NPC's that have argued it.
The use of negative energy is not evil in and of itself.