Get an aggressive agent with a good reputation who knows your market and who is not afraid to ruffle some feathers. Then get a great inspector for your home inspection and you should be on the right track.
You must WANT this house!
This is an exercise in self abuse.
You are using the Listing Realtor
On a Shortsale
With an unfinished addition
That has no permits
You don't know what the house is worth,
And you don't know what the house will be worth IF you can ever finish the work,
And you undoubtedly will not get it passed the Appraisal.
Good luck and may God bless