I think Maleficent was able to turn into a dragon at will in Fairy tale land. So she wasn’t stuck in her dragon form after Charming put the egg in her. But when everyone got to Storybrooke, Maleficent’s cursed self was her dragon form.
I’m pretty sure he did, I don’t think this was actually addressed on the show, but I believe the writers have commented on it. I think that’s why he was seeing Archie in the first place, because Regina wanted Henry to think that there was something wrong with him and not the town. Also I think that’s how he started to think the book was real.