I agree on your first two paragraphs, that was all made for TV edits I'd bet. This whole scene might be fundamentally different, why is there even a door in a cave of dryad people who are one with nature and shit. Maybe there'll be a complete different door. GRRM has confirmed the door part though, not just through the elevator thing Ast posted but in the hbo behind the scenes right after the episode.
But no dragons, sorry. Just someone from season 1.