Texture on outside of objects (changing object silhouette from materials)

Yes!  This process is called displacement. 🙂  I made a note to write a guide for our documentation on this feature but here's the short version:

• Add your object/model
• Apply your materials.  The material needs to have a 'height' map.  For most Substance materials this will be generated automatically.  If it's a custom material you're making you'll want to create a grayscale image where gray is flat, black is recessed, and white is protruded.
• In the Stager interface select the object, go to the properties panel, and select the object properties tab.  Scroll down if needed and enable the displacement section.  You may not see any effect YET.

• Switch to the material tab
• Scroll down to the 'height' section
• Adjust the height scale
• Potentially adjust other things like material tiling
• Witness the glory that is displacement

Note that in the object displacement settings you can also control something called tessellation.  Tessellation is a process that basically controls the resolution of the actual 3d surface so it has enough geometry detail to represent the material.  Lower tessellation will be faster but 'chunky'.  Higher tessellation will be slower but show all the fine detail.  You can setup tessellation per obejct so you could have less geometry on background objects, for example.