Impac Mortgage is ready for a slimmer mortgage marketplace, but it didn’t have to do much but keep believing in its decades old business philosophy: Compete with product and service, not price. “The longevity of a company is not based on just a purely transactional environment,” said Diane Keane, senior vice president of sales. She calls upon her 30 years in the business to support the contention that the mortgage business is built upon relationships,…