FirstKey Mortgage, which has big plans in the non-agency space that include lending outside the qualified mortgage box and securitization, late this week saw the departure of three of its top executives, including CEO Bruce Witherell. According to industry officials familiar with the situation, FirstKey’s parent company, Cerberus, was beginning to take more of an active role in how the lender/issuer was being operated, a situation that didn’t sit well with some senior executives at the nonbank, including Witherell. Witherell and FirstKey executives Randy Sidhu and David Essex have accepted...