...I wouldn't say I've discovered anything, no. But some theories have been formed; I'm surprised you haven't come to any sort of conclusion yourself.

The shorter version is this: I think you're on the right track with the Gym Leaders, given that they hand out the badges that will allow us to face the Elite Four and presumably return home. But take that one step further for a moment - let's assume for a moment that acknowledgement of your victory from the Elite Four isn't some sort of prerequisite for whomever is keeping us here to allow us to leave, as there's no verification of that one way or another. All we know, as far as these rumors go, that if we defeat the Elite Four, we can leave.

Isn't it possible that the Elite Four themselves are the ones keeping us here? They're supposedly the most powerful trainers in the region; control over these chimeras means control over Johto. We don't know what sort of powers all these chimeras actually possess, either.

I have reason to believe that interrogating the Gym Leaders would be a waste of time; we should be focusing on the Elite Four directly. Find them, find a way out. Simple as.