I'm very sorry, I have only just caught up with this thread.
As you can see there are many ways that people think of their dogs and what their dogs are telling them. Many also misunderstand the classical terminology that is attatched to dog behaviour - the most common misunderstanding is the use of the word dominant.
Your dog is doing it's very best to take on the dominant role in the house as you are giving it signals that you are unable to cope with the role. It therefore believes that it is responsible for your wellfare at all times and when you leave it alone it is unable to take care of you in the way that it thinks it should. To try and cope with it's panic it is marking it's territory VERY well in an attempt to make the home safer and better protected from the outside world. It is chewing and destroying furniture to further release it's feelings of stress and panic.
The only thing you can so to help your dog is to take away the responsibility by becoming a more dominant animal than your dog is. Your dog has taken on it's role because every pack needs a leader to survive as a pack - as nobody else has taken the role your dog feels it has to. It has no idea how to carry out this role in a world of humans.
I suggest you get a behaviourist to help you as soon as you can - crating your dog will confine it's panic and worry not end it.