1) Yes you can, ofcourse it depends on how vivid the dream is though.
2) Yup you can, but don't worry it's not going to be life threatening pain.
3) Yup you can. It's amazing how your mind works, it usually decides on how the object/event should feel and then compensate for it.
4) Depends on how vivid the dream is, some dreams feel real and some don't.
5) No there's no danger, well no more then normal dreams.