I really liked your dimension idea. It really brings out the multiverse theory. Would you only be able to see into said dimension or could you jump into them as well?
I really liked your shadow idea. Its like you're never alone. And who better to know when you need comfort than your shadow. I'm curious to see if the shadows will have feeling of their own. And maybe get jealous of people who try to comfort their person.
my favorite what if idea was "what if you could sell and buy dreams." It is very intriguing to me. It makes me wonder, do you have to buy dreams to be able to dream? who makes the dreams? Can you still have dreams of your own? Can you sell your own dreams to other people?