Meh. Most likely, the RPGA is filled mostly with players of Humans, Dwarves, and Halflings, and a smattering of others, because the low point-buy used in RPGA games combined with the poor game-mechanics design of other core races makes them rather seriously disadvantaged.
Elves, gnomes, half-orcs, and half-elves just generally suck by comparison stat-wise for such games (and most folks aren't fine with their character sucking most of the time in actual play; especially in games like the RPGA, where the DM doesn't have as much freedom to help out such characters if he or she is so inclined).
So statistics from the RPGA wouldn't really be telling, since many folks not participating in that have home games with a broader variety of races used because they don't use heavily-restrictive ability score determination. Of course there are some folks that still use the 25-point buy or similar, too, but probably not as many.
As for the halfling-name point: Yeah, in some settings they have their own name for their race. In Faerun they're called Hin, at least by some of their own kind. In my Rhunaria homebrew, the halflings' own name for their race is Keth, but with many of their kind being wandering traders and explorers, they don't cause any trouble with other folks calling them 'halflings'. Besides, halflings are probably just fine with other races dismissing them and underestimating them; it makes it all the easier for them to live relatively undisturbed and also makes it easier for them to engage in shady or revolutionary activities.