I was considering Taillow as a starter, we'll see. Ralts currently isn't obtainable, hence why it's in brackets in the obtainable list. That's because there isn't actually enough credits in the game to afford it right now.
The clue IS slightly misleading, well, it was Shiv that made the puzzle after all.
Dawn Stone? Episode 2 and people are asking about the Dawn Stone? I think you're in for a long wait buddy.
Edit: No, 2.1 does not add any new content. It's simply the polished version of Episode 2.