Hello, the Asphalt material is an old one made from NDO, thus not originally a scan. That's why it has some shadows in the Albedo. We will replace it soon :) .
afair e_defaultmaterial changes all textures to a grid texture, but you can change the texture to white by replacing the original (cant remember where it is though, sorry)
For the images, just upload them of a hosting site, and do this [img>IMAGE URL HERE[/img> Replace the > with closing brackets. Good luck with your project :)
http://www.zbrushcentral.com/showthread.php?62618-MatCap-Tutorial-by-KOSOVA Alternatively, you can just copy an existing matcap, open the modifiers, and replace the image used
-dublicate the object that has the transform you want -select that object than the object you wished had the proper transform values -modify > replace objects.
why dont you try with material instancing and then replacing the texture for each material instance? or do you mean they should animate to show random textures?