Trying to find a a clarification.

If you have two-weapon wielder Ballistic can you fire two pistols on full auto?

Yes,

This is a full round action

According to the errata (p. 11), you don't need the Two Weapon Wielder (Ballistic) Talent in order to fire two pistols at the same time although it does significantly reduce the penalties to your off-hand. The second last bullet point on p. 197 of the DH core allows you to fire two ranged weapons in different modes and implies that there is no problem firing them both on Full Auto.

So many cinematic moments open up with this simple concept.

I would like to note that according to pg. 190 only "pistols" may be fired full auto in this manner, so no dual Autoguns with recoil gloves.

However, according to pg. 197 you can lay down some suppression fire with one weapon, while pumping a specific target full of hot lead with the other. It gets a little tricky since the maximum range of suppression is 1/2 the listed range of the weapon (not much for a pistol), but still makes a great "hello" when you accidently stumble into a room full of cultists.