Good.
Possibly. But don’t let the perfect be the enemy of the good.
And note that you’re applying scientific concepts of evolution to groups that can include machines, sentient rocks and beings made of planar energy. That doesn’t strike you as somewhat … extra?
Sounds too quaint to my ears, but that’s a minor quibble.
“Kind” works too, but also too biblical. “Lineage” and “heritage” and “stock” are also alternatives used by other games. They all share some of the baggage of “race”, though.
The actual article linked to already used what I consider the best alternative, though: “people”. “Playable peoples”, it said, but the “playable” isn’t needed. And it has a nice Tolkienesque flavour:
Learn now the lore of Living Creatures!
First name the four, the free peoples:
They’re literally not humans.