No, you absolutely can not edit your personal statement once you submite to one school.The AACOMAS application will have a disclaimer you have to aknowledge before proceeding with your application submition claiming that you understand you cannot edit some sections once you submit. Two of the sections you cannot edit are both the activities and Personal statement. You can add activities, but you may not edit them. There may be a few others as well. You can look it up on the AACOMAS website if you really want the information from the source.