D&D isn't necessarily high fantasy, but I can see your point.
Oh yeah, totally not racist!
I had ape-men before, but I felt they didn't really fit the vision I had for the overarching race, being more "primitive savages in a jungle" than "adaptable and ambitious pioneers" (though admittedly, the Drow don't exactly fit the picture painted by the Elf description either…) Still, based on your suggestions, I guess I could play up the "ancestors of mankind" angle.
Nah, sorry, but not only are those roles taken by the Drow and the Halflings, respectively, I'm not gonna directly rip off H.G. Wells here.
This, I like. It might be treading on the Elves' toes a bit, but it's unique enough to work.