That's something I consider as well. I like having certain species be best at certain things, but there should be a variety of options. There are many big, powerful species -- giants, ogres, minotaurs, ettins and dragonspawn -- who would be great as fighters, but then what's the point in being a human fighter or orc fighter? My answer to that specifically is that smaller species would still be balanced by having slightly more agility, speed and perhaps accuracy, so by playing them, you wouldn't just be shooting yourself in the foot. Also, the different big species I mentioned have different talents. Ettins can dual wield shields, and are best at dual wielding one-handed weapons, though they perform poorly with two-handed ones. Ogres can eat corpses and rotting meat. Dragonspawn have some talent for magic, minotaurs would run fastest of all the big species and be best with throwing weapons, and giants are balanced between melee and bows.

My answer to the abyssal elf question is that both dark elves and abyssal elves could be talented necromancers or warlocks, it's just that culturally, abyss elves have warlock as their school while dark elves have necromancy. But with magic, it's more complicated, and merfolk and tengu basically being designed for water and air respectively poses an issue in my mind which I'm unsure of how to resolve. I'm thinking that perhaps wood elves would be good with water and air as well as nature magicks, giants would be good with ice and thunder and air, the catfolk question would have to be resolved by them having a tradition of wizardry... bah, screw it. I'm still confused, LOL... I dunno though, maybe I can figure it out soon.

With what you said in mind, though, perhaps it would be better then to refrain from elemental elves, then, since it would give people more of a choice in choosing who or what to play as.