What are the possibilities of getting a green card after a stokes interview?

Well, if you were missing some original doentation and you were asked to return with it, I imagine that's what the second interview is all about. I don't see any reason to read too much into it, unless, of course you can't provide these doents. but as the others have noted, if you're living together as husband and wife, you really shouldn't have too much difficulty in getting approval.