To the OP:  I honestly don't have the words to say all of I what feel about this thread.  You have asked some excellent, thought provoking questions.  I am impressed with how much thought you've put into this (& I know you have because I've thought of several of the same points you make here, but you make even more that I haven't thought about).  You also seem to have a 
realistic yet positive view of pups in rescue and I thank you for that as well.  Overall, I guess my point is - GREAT THREAD!!! 

  It's given me a lot of stuff to think about. 
    
				__________________
 He is your friend, your partner, your defender, your dog. You are his life, his love, his leader. He will be yours, faithful and true, to the last beat of his heart. You owe it to him to be worthy of such devotion. -- Author Unknown