Separation anxiety and urinating in the house

Question
We rescued our chocolate lab/shar pei mix from a shelter. Clearly, she has been abused.  She shakes and pants whenever she knows we are leaving.  She has gone through two crates (one metal and one plastic), literally chewing her way through to where the walls were splattered with blood.  The last incident left her cut all over as she managed to squeeze out of the hole she chewed open.  We decided not to get a third crate and instead leave her out, closing the bedroom and bathroom doors.  She then started to claw through the wall by the front door, leaving a gaping hole down to the wires inside.  We put a large wooden panel there and she seemed to do fine as she doesn't tear anything else up.  But we just realized that she is urinating in the same spot by the front door.  We are about to move to a new apartment soon and cannot have her doing the same thing there.  I am at my wits end, she is great otherwise, not aggressive, doesn't beg, knows commands and walks fine.  But the urinating and the clawing at the wall cannot continue and I will have to give her up if it doesn't stop.  Clearly, I don't want to but I don't now what else to do.  Help!

Answer
One of the most frequently used resources is this inexpensive little book: "I'll Be Home Soon - Preventing and Treating Separation Anxiety" by Patricia McConnell.  This is a difficult problem to solve, but not impossible for a committed owner.  The fact that the dog destroys the area near a door indicates to me that she is trying to get to you (her only security).  The urination might be from fear, she might be inadequately house trained, or she could even be spay incontinent and leaks urine while sleeping (probably sleeping at the door at the last place she saw you).  The fact is that a new location will probably make this dog more anxious, not less, so you might have the same issue.  Crates seldom work with SA dogs.  There is a protocol by John Rogerson, if you can find it by Googling, that has worked well for many owners and their dogs.  Here's a synopsis of the method by Dee Ganley, who trains in NH:
http://www.deesdogs.com/documents/teachingyourdogtostayhomealone.pdf
And, more sep anxiety resources on this page:
http://www.k9events.com/behaviourS.htm
Good luck!