Is the franco benoni playable?

This is madness!

It's good for White.

Oh, wait, I actually play that opening!

oh yah!!!!!

do grandmasters play that opening?

I do not play that opening, but nobody cares.

e

that is true.

Black more often plays ...g6 & ...Bg7, which makes the position superficially like a Benoni (it certainly doesn't resemble any French), but there are some significant differences. 

First, White saves the tempo c2-c4 for development because this doesn't arise out of the typical move order for Benonis.  Secondly, as a result, there is not the usual Benoni counterplay with a Queenside majority and half-open e-file with a target on the White e-pawn.  The open e-file make it resemble a KID more, but still without c4.

White gets a small but durable advantage, mainly based on space.  Black is somewhat cramped, so the last thing White wants to allow is a general exchange of major pieces on the e-file.  To this end, in the game presented, White should just develop with 11 Bf4 so he can play Nc4-e3 without shutting in the Bc1.  Also he will wish not to oppose Rooks on the e-file too soon, since exchanges will help the cramped opponent.