Rights （for commission介词插入语） will not be payable if seller states that （宾语从句appropriate extra-judicial ensures to effect payment have been without result.）
effect payment 履行付款
extra-judicial 法庭外的
如果卖方说明正当的庭外确保履行付款没有结果的话,那么收取佣金的权利将无法得到履行.
是的,宾语从句的谓语是have been