In the case of a short sale, absolutely the Seller is responsible for full disclosure. The PR will identify all issues regarding title including all liens and your lender would not approve your loan unless all of the liens were cured.
I do not really understand why the listing agent is reluctant to show the house. I have not had that same experience. I have had no problem showing clients short sale homes. If you called that listing agent and asked them to show you the home, and you told them you were not represented, they should be encouraged to show you the home as they can get both sides of the commission. However if you told them you wanted to see the home, but that you have an agent, then more likely that listing agent will ask you to get your own agent to show you the home. If this is not the case then yeah it is a lazy agent.
Regarding the MLS listing you posted about. From the tax roll on 9/2005 there are two recordings, it looks like a first mortgage for 620k and a second for 155k. The home is currently listed at 600k-625k. That is a nice little bath the lender will be taking.
