Oh no!

You forget that after

1.d4 c5 2.Nh3 d5

White can play 3.e4! and transpose into "The Brick"! 

There is a thread in the Anti-Sicilian section, go have a look

In keeping with the less common lines previously posted by Gambit, and to finally finish my 5 cents worth here, there are two other lines of concern that White might have to face. I believe that some strong players have not been afraid to spit out these out at White from time to time.  These are: 1.d4 c5 2.d5 Nf6 3.Nf3 c4 called the Hawk Benoni and 3.Nc3 Qa5 called the Woozle. Now, that should keep us busy for awhile !  Keep us abreast of any real findings in this labyrinth.

I guess I should qualify that last post by saying I would TRY for a Schmidt Benoni. I could have to face a closed Benoni or a Czech Benoni after 1.d4 c5 2.d5 e5 3.e4 but that may not be too worrysome unless a very strong player was moving the Black pieces  . Then there are the lines 1.d4 c5 2.d5 Nf6 3.Nf3 b5 or 3...e6 or 3...g6. The Schmidt Benoni was recommended in Modern Chess Openings by Lane and Killer Chess Opening Repertoire by Summerscale. However, they did not spend much time on the other lines you would have to wade through to get to the Schmidt Benoni. The Schmidt has been played by some very respectable GMs including at least two World Champions that I can verify (Karpov and Botvinik). Did Lothar Schmidt write anything about this opening ?

LOL!

From 2.a3!? to 2.Nh3!? I can see another dozen moves waiting to be 'named after'

Obviously, 2. d5 is best. But sometimes it is followed by that 2..., f5 thing...

After 1.d4 c5 2.dxc5 e6 3.Nc3, I am pretty happy when Black takes the pawn immediately:
3...Bxc5 4.Ne4 and I will have two bishops

Otherwise, he has to spend some more tempi to get back the c5 pawn. Meanwhile, White develops like in the Sicilan... Not a big deal, but a playable alternative to the closed and complicated positions after 2.d5

Actually an early a6 happens in a lot of lines in the Morra. Personally I don't think that it'll make a lot of difference when it's played, I can't see any way to take advantage of it as white's first few moves are fairly fixed.  Maybe white could try to find another square than c4 for the bishop so that b5 is less effective, say with Bd3, but I don't believe it.