davis only had all the control over whether war would come and how it would be waged. He didn’t have quite as much control over when he would surrender.
He *DID* fire on Confederate ships when he was there. He stated unequivocally in his memoirs that when he arrived, it was his intention to sail along the shore and rake the confederate gun emplacements with shell and shot. He was only stopped from doing so by Captain Meigs, who put his ship in the path of the Powhatan and got Porter to stop.
Porter recounts that he very much felt like running Meigs over with his ship, but finally chose to heave to.