Something just occured to me about why tobi wears a mask and cloak to begin with.
It may not have anything to do with hiding his identity obviously now since madara is summoned it would be a good idea to keep his face hidden but before the kabuto summoned past kages(that know what madara looks likes) and madara himself people wouldnt know what madara looked like anyway his cover wouldnt be blown.
So I'm thinking his great lengths to hide his face and body is to not allow the enemy see his physical weakness.
I think like nagato he is damaged. Like all that "Im a shell of my former self" talk. Tobi himself dosent use much chakra in fights, you never see them do many jutsu or exhaust himself by using strong jutsu that you would expect from a villain.
Also I think even if tobi takes his mask off we still may not know who the hell he is until madara/kabuto or himself reveals his name.