It is a HUD home and was definitely not disclosed.

I want to flip this property, but I'm afraid that if I disclose prior mold issues and I say I cleaned it myself, they would be afraid and I might loose potential buyers.

If your state required such disclosures, you certainly should have disclosed the leak.Mike

Has anyone ever disclosed closing costs to an end buyer who has not signed your assignment contract, or put down a deposit with the title company?

The applicant has already disclosed the past issues (interesting) but likelihood of repeating it.It's your screening so handle it accordingling.

Without a binding offer to purchase, why should the owner disclose anything at all? 

The survival of one of the nation's largest non-bank mortgage servicing companies was thrown into question Thursday as the company was hit with federal and state lawsuits for allegedly failing borrowers with mistakes, shortcuts and other problems that cost some people their homes.Ocwen Financial Corporation allegedly botched basic functions such as sending accurate monthly mortgage statements, properly crediting borrowers' payments and handling taxes and insurance, according to a lawsuit filed in a Florida federal court by the Consumer Financial Protection Bureau.The CFPB also accused the company, based in West Palm Beach of improperly foreclosing on struggling borrowers, ignoring complaints and selling servicing rights to mortgage loans without fully disclosing mistakes the company and its subsidiaries made in borrowers' records.Read full article here...

A lot of the negative things she self disclosed turned out to be smoke screen for the things the credit bureau told us.

. $350k deposit paid upfront but upon looking up county records (Santa Clara area), sq. ft. of lot is ~900 sq. ft. less than originally disclosed. 

State law will dictate the requirements for what stigmas need to be disclosed.