About number 3, I think that after the dreamworld and real world are combined all humans are just going to sleep normaly and since most do not know about lucid dreams they will think that its just real life or a dream, while LDers are the ones that will get "powers" and all that stuff.

About the illiness part,I think is cool, maybe that is starts like some kind of nightmare, well it all depends on what happens to normal people. But I like that idea.