Recently, your project exceeded its estimate and the customer insisted that you and your organization absorb the extra costs. Is this fair?
1) No, but since you do not want the customer to sue your organization, you should pay the costs.
2) It depends on the way your contract was written, but probably the customer is correct.
3) Usually the performing organization and the customer split overruns 70/30.
4) Ask the customer if they will pay the full amount this time.