VAS and VDM of vision

Hi Sir, 

I have a question for the vision setup, this is a general question.

So usually as long as we have VDM, then we can code with labview, and VAS is not neccessary because it is just a intelligent tool to create the code, right ?

Besides this, how the NI MAX to recognize the camera ?

Need what kind of drivers ?

The last question is that, vision can extract the content of a QR code, or normal barcode, right ?

Thanks.