think about this. Tolkien creat elf, Dungeon & Dragons took the elfs and did their versions, and WOW did that to, and other did that. And no one care, because everyone creat a different mythology and world.
If the world is yours, then go for it (but of course it will have in part, some of the tolkiens ideas).
PS: even more, elf were created be tolkien as a interpretation of a mytologic elf.
Using WoW as an example of what is not plagiarism is a very bad idea. WoW is almost entirely devoid of original thought. Nearly every single thing in that game is stolen from Warhammer or D&D. There's a bit of innovation here and there, sure, but when it comes to illustrating the difference between being inspired by something and being a nigh-plagiaristic rip-off, WoW is firmly in the latter end of that spectrum.
The relationship between the first Starcraft (but dear god not the new one) and Warhammer 40k/Aliens/OtherSF is a good example of being inspired by something while still being original and not derivative.