Yes, it is paintable
The application temperature is 180-200 C, while the softening point is approx. 100 C.
Yes. Light sanding is recommended but not absolutely necessary.
We do produce darker material, such as Mahogany and Walnut, but they are not sold through Home Depot.
The edgebanding is only .020 inches thick, which is 0.5mm. It does not add much to the edge of a shelf.
The veneer is about .020" (+/- .002") mm thick before the application of the hot melt adhesive. The veneer and adhesive combined are about .032" (+/- .002")
Yes, this can be glued to a replacement composite window and it can be stained.
The image is a picture of the veneer coil. I understand that the specie cannot be viewed itself in the photo. The specie is Red Oak, which you will be able to find an image by searching "Red Oak Veneer" in any search bar.
Yes, you can cut the edgebanding with scissors the the size you need to apply to your stairs. We would recommend to scuff-sand the laminate before applying the edgebanding.
You should be able to order it from any wholesale supplier that sells plywood. Not many places keep it in stock as it isn't a high selling item and is easily damaged when trying to stock it at a lumber yard. Of course you will have to buy a whole piece, they are generally 4' x 8'. If you want to recover some of the cost, you can try to sell the remnants on ebay or other online source.