Healthier Banks Cause Agency Cutbacks: The Federal Deposit Insurance Corp., recognizing that banks' financial condition is improving, said it will close most of its offices and cut half the staff in the division that sells the properties held by failed banks. The drastic restructuring of the liquidation division, to begin next month, aims to save the agency $430 million by the end of 1997 and $170 million a year after that. When the realignment is completed, the Irvine office will be one of only five service centers nationwide handling the assets of failed banks. Fifteen of 22 offices will be closed: in Encino and San Jose next year and in San Francisco in 1995. About 3,300 of 6,600 employees nationwide will be laid off.