I am not sure why the owner wants to remove the sink if only for more room but when the boat was being designed, it was not only to have a traditional sink in the head but that was a preference by the women to wash hands, brush their hair and so on. In addition should the sink be removed, resale value will go down the tube and many will veer away from purchasing the boat. If the owner should persist in removing the sink, to leave the bulkhead alone to the right and most definitnely the floor as he would be getting into structural issues. If removed there would have to be work to hide removal on a professional standpoint.