Great thread. I'm a C-17 driver and always wanted the C-17 to be FAA type rated. It is an incredible machine that can do some amazing things but those capabilities are not necessarily commercially viable (air refueling, IMC formation airdrop, aircraft armor and defensive systems). Remember this aircraft was designed as a millitary machine for "direct-delivery" of oversized and outsized cargo from stateside bases directly to the front lines.
I agree that there seems to be a very small niche of civilian airlift work that the C-17 would be profitable in doing but I know that it would do it very well.