IS DEMONIAC SPIRITS REAL?

My understanding is energy that flows from the infinity ring of life has multiple layers, each chakra of our own self has the same vibrational notes and layers, there are 7 heavens each with their own Angels and Daemons.  Angels and Daemons are very much the same thing, just as they can inhabit the 7 heavens they can inhabit the 7 Chakra points of the Human frame.  Each of these creatures grows through experience, many of us have unknown unions with these astral beings, yet some of us do become aware of our higher or guardian Angels.  Most people don't have each Chakra inhabited as their Chakra and energy flow is not in tune.

DO THEY IMITATE LOVED ONE'S THAT HAVE PASSED?

There are Astral beings that I feel could be indiginous to our world alone, much like how we are, a race of what is known as the Djinn, these creatures I said to whisper into the ear of man, causing negative affects that will affect the human energy flow enough to remove the energy beings of the universal energy so they can the place of that energy.  If I was to label these Djinn, I would could them parasetic, they thrive off of negative energy, yet they are ancient, and can give insight and knowledge in return.

ARE WE PROTECTED IF WE OPEN OURSELVES UP TO THE SPIRIT WORLD?

Depends what you do and how you do it...  
(It's like asking is it safe to cross the motorway on foot... It is if you use a bridge...)

DID THEY ORIGINALLY HAVE A BODY OF FLESH?

According to the Quran the Djinn had a physical form but due to their destructive nature it was taken from them by the creator and then the Djinn where cast into a dimension off set to our own... Due to their current situation they have no real respect for the creator or energies directly from it, and as the Human race has replaced theirs they love to toy with us.

Fallen Angels/Daemons to me, is just a term to understand that the energy they consist of is nolonger connected to the infinity energy flow of the universe.