Wow. People have some great theories! I still feel really in the dark as to the whole situation surrounding Belle in SB. I think TPTB just put in that one little scene with her and deliberately left it ambiguous just so we would drive ourselves crazy trying to figure it out! One thing I do feel certain of — I don’t think Mr. Gold knows about Belle. That is such a huge reveal and a huge moment, I would feel really ripped off it had gone on behind the scenes and we are never going to get to see it. I think it will be a game-changer for Gold for sure.
As for Belle’s reaction — so much depends on what her experience has been since she left the Dark Castle. If Rumple had gone after her within a short time, or even if he had caught wind of her father locking her up, etc. (if that really happened), I am confident that Belle would have given him a second chance, and given their “true love” a second chance. But without knowing how she was affected by the curse, it is impossible to know how she will react to him. Really, we know Gold/Rumple so much better as a character that it is easier to predict what he will do. I hope we get the chance to get to know Belle much more.