Adding a couple new races, or even making existing ones playable, could freshen up the RP in the world and, I think, would be simple enough to implement.
How about playable orcs and goblins? Come up with some RP excuse like, an offshoot of the horde, transformed by Moradeim/Entities/Avasyu's biceps/etc to be more intelligent and less hostile to civilization. Maybe I'm just a little biased towards this because I think goblins are adorable (and I would love playing one.)
Hyena-like humanoids, evolved from humans that settled the Heartlands?
Spider-like humanoids, ancient racial enemies of the akrabi, with the ability to secure their wielded items with strings of webbing (or spit it at an enemy as a weak entangle?)
Shark people that are distant cousins of the lamira, with an innate powerful bite attack?
Monkey people from the ruins of n'Aryanvella?