Consumer advocates and lawyers warned federal officials in recent years that the U.S. foreclosure system was designed to seize people’s homes as fast as possible, often without regard to the rights of homeowners. In recent days, amid reports that major lenders have used improper procedures and fraudulent paperwork to seize properties, some Obama administration officials have acknowledged they had been aware of flaws in how the mortgage industry pursues foreclosures. But the officials said they could take only limited action to address the danger. In part, this was because they wanted lenders’ help carrying out federal programs to modify mortgages that had fallen into default or were poised to do so.