Lewis is very unclear on this, so it’s always a very debated issue. Most lean toward her being a different person, due to their personality and powers being very different.
No he didn’t. He read probably the first few chapters of The Lion, the Witch and the Wardrobe, because he objected to the mixture of our world with the fantastical world, with the Fauns, Father Christmas, etc. I am not sure about this, but I remember it might have also had to do with Lewis’ alteration of the Faun from the mythology of the time, to fit his needs.
He had an image in his head of the Lamp-post and a Faun carrying a few parcels next to it. He started with that image and created a story around it.
If / when they decide to move on with the movies, they’ll announce the next castings via casting directors.
Because in the books they leave Narnia as well, once they reach a certain age or have learned all that they need to from the land of Narnia.
Because I wanted to check to find out if it was really him. It turned out that it wasn’t.
Wherever they are holding them, if they do that one. It could be a few years, though.
Lucy, Edmund, Susan and Peter appear again in various Narnia stories. Sometimes in very small cameos, but they do appear.
He has e-mail, but it’s not public. Sorry. As for Facebook, that’s just for his family and friends.