As for the races:
The amount of races in a setting is solely on the DM's shoulders. Of course, in a Darwinian world like ours it would be highly probable to see that many races survive and thrive. But we play in worlds where magic exists and gods are real. A god is angry with a nation? Well, he opens a portal to a world where orcs are abundant! Or maybe he opens a portal to a worlds filled with dragons and pick one (or a few) to throw at the nation just to show them to show proper respect. A few members of the invading horde survive and voilà! A new specie is walking the face of your fantasy setting (and maybe a few more dragons...).
As for the gender related stats.
I began to play in the early 80s with AD&D and these were the norm back then. This is a fantasy setting/game. I have women as players and I don't want them to be pushed into the same classes over and over again. I currently have a female dwarven barbarian and female human monk in my group. I don't want to gimp one or the other for the sake of realism. This is fantasy. And if it happens that a women can be stronger than a grizzly bear so be it! More over, I prefer to see high stats being the way you use your strength/dexterity (or whatever stat it maybe) than a real potential. I would not return to that way of creating/playing characters.
As for the Tiefling and other non standard races...
I always had a bad feeling about them in any of my campaigns. Although I don't restrict their appearance, they do come from either demonic or infernal stock. They face a lot of racism from the townsfolk (even more than half-orcs do) and are often attacked on sight unless they are accompanied by some holy men from a ''good" religion/cause. And even then, everything must go smoothly in town or the tiefling will be accused of wrong doing. I do play in Greyhawk and many races suffers from racism in human towns. Half-orcs, Tieflings, Drows (which will be killed on sight). Even looking a bit to much like a pure Suel will get you strange, unthrusting, suspicious looks (for their role in the Greyhawk wars). Gnomes will raise eyebrows as will dwarves, elves and half-elves. People will not be afraid of them, but very curious (and sometime they will flirt with elves and half elves). My campaigns are humano centric but I do allow a lot of thing. The player must be ready to live with his/her choice.