2) How will you prove that the seller new this and hid if from you?
3) Why did your inspector not catch these issues?
4) Why did you not sign an arbitration agreement?
Arbitration would certainly have been a form you should have signed because it is cost effective, and as long as you can prove the seller hid a material fact from you I think you have a pretty decent case of winning. It must be obvious to prove that the seller knew of the issue and essentially hid it from you that is the key to winning.
And I agree with Tim keep searching attorney's. The other thing you can do is go to the commerce department and file a complaint, and also maybe even go to the association that the listing realtor practices and file a complaint.