From what I read, the part of your brain that manages writing and reading is unconcious while you are asleep, and therefore, doesn't work properly.
This is why reading a text and then reading it again to see if it's changed or if it's hard to read is a well-known Reality Check. That's probably the reason you're having trouble writing.

As for the passing through things. That's a Reality Check too. ^.^ This works by for instance trying to make the right thumb go through the left hand.