Basic hand drawn illustration
This Basic package includes one black and white drawing
For bigger projects yes, I do offer a small sample for free. But generally it is something that depends from project to project.
If you are a company selling a product and the image I create is promoting in some way your product, than the answer is yes.
No. In the case of a book project (or any other bigger batch) the Commercial license is set by mutual agreement as a fixed fee and it's not calculated per image.