Mortgage-related issues will likely play a central role in the end product of financial regulatory relief legislation working its way through the U.S. Senate. For now, though, the measure passed by the Senate Banking, Housing and Urban Affairs Committee last week is really an opening gambit, as congressional staffers confer over technical details and lawmakers horse trade and arm twist. “It’s a starter,” said Bob Davis, head of mortgage markets and the senior lobbyist at the American Bankers Association, speaking of the bill sponsored by committee chairman Sen. Richard Shelby, R-AL, the Financial Regulatory Improvement Act of 2015. “The Shelby bill will be...