I think this is fantastic.
Personally I would feel that it is not necessary to balance all the races. Some creatures are just... Better than Humans.
A thought of change two of the Genasi:
Air elemental would be to have them (slower or faster?) during storms, while also allowing them to be further persuaded by the force of nature to be shoved around, like a stronger version of the sandstorm's powerful wind.
Water Genasi taking ticking damage while in hell, being evaporated. While being slowed in snow biomes due to their bodies solidification in the colder climate. ((A comical idea. But in Multiplayer, if Water Genasi are showered with the water-gun (purchased from the traveling merchant) they would heal? Questionable for Water bolt being that it is hostile magic.))
An Additional race being Immortals (or Demi-gods if you'd prefer to give them the title)
They essentially harbor the looks of a human with minor differences being their eyes are a solid color. Optionally they could may animal heads like some of the more ancient demi-gods like the Egyptians.
stats being roughly
10% resistance to magic
**Glows in the dark** (the color of their eyes?)
Immune to Poison, & Stoned
summoning damage increased 10%
And as for debuffs, the only thing i could perhaps think of is Burns for Longer, with increased damage. Taking more damage from melee as beheading them would be their end.
That is all I've got to share! I enjoy this mod very much and hope to see it flourish! ((Really looking forward to being a 2block tall Kobold.
))