I think the Dragon knows some things. Mostly lots about prophecies made about them, he's been around a long time. He knows a bit about their future and destiny, but a lot of things aren't set in stone, which is why Merlin has to actually go out of his way to save Arthur time and again. The future can still change and characters can still die. (Though it's unlikely they'll kill off certain characters).
I know that all Morgana will likely know (unless from dreams or something) about L/G will be from the end of 1x09.
|That's why I keep wondering why it was necessary for M&M to tear the veil? Surely, Morgana would be able to sneak into the Castle, kill Arthur and get her revenge. Tearing the veil seems to be an extreme act of large and potentially uncontrollable scale to commit in order to bring one's « enemies to their knees » The obstacle of getting the people, knights and army to accept her as queen would be no less present, with or without the Dorocha in the world of the living.|
|Was it her plan to show up in Camelot, promise to solve the problem of the Dorocha, sacrifice some poor lad and close the veil, then be welcome to Camelot as a saviour and queen ? Not likely, as people would still remember her "reign of terror"|
I don't think either were immune, but she might've been taught by Morgause some magic to protect herself from them, or her home. Also I don't think they were above simply letting the masses of people fall, with them mostly hidden away or in his case, surrounded by others.
She probably planned to sacrifice someone to close the veil if it didn't happen otherwise. Also she might've just planned to have the entire population of the place dead. She is an extremist and seems to have gone a little mad, also (IMHO) though she wasn't evil from the start, she was always selfish.