There would be a TINY ;-) problem with this approach: Fort Sumter was most definitely NOT State of South Carolina land! Fort Sumter is in the middle of the harbor of Charleston, South Carolina. It's a fort built on an artificial island...both the island and the fort were created with 100% federal funds. (According to the Fort Sumter historian, who I contacted a while ago.)
This is what South Carolina should have done: Union troops abandoned the land-based forts that surrounded Sumter, because they knew those forts couldn't be defended from land-based attacks. The State of South Carolina occupied all those land-based forts. Those forts all had commanding positions virtually surrounding Sumter, and could Sumter to bits in a matter of hours (which they did, to start the War).
South Carolina should have allowed Lincoln to resupply Sumter...forever, if necessary. South Carolina should have just gone about its business. Sumter was absolutely no threat to ships entering and leaving Charleston, because the minute Sumter fired on any ships, South Carolina shore batteries could have ripped Sumter to pieces.
Lincoln stated in his First Inaugural that he did not agree that the Southern states could secede...but he also pledged not to harm them, if they didn't interfere with legitimate U.S. government actions. (Like firing on and capturing Ft. Sumter!) South Carolina should have held Lincoln to his word. They should have forced Lincoln to draw first blood (metaphorically, as there were no deaths from South Carolina fire, in the initial taking of Fort Sumter). They should have let Fort Sumter be re-supplied for...the next 100 years, if Sumter never fired on any shipping.
The only flaw in that scenario is that until Sumter was fired on, only 7 states had seceded, all in the Deep South. None of the Upper South where opinion was very divided had yet broken the Union and Davis was beginning to feel pressure. Without more members, especially Virginia and North Carolina, there was danger that the Confederacy would not be a viable entity.
Davis needed to move events that had been basically stagnant since January. Lincoln had been in office for over a month and had taken no overt action against the seceded states. With more time, the "Black Republican" propaganda that had whipped the majorities in the seceded states into supporting secession would wear off as people had an opportunity to see that Lincoln was not what they had been told he was. Davis knew he had to force Lincoln's hand or the Confederacy could have likely faded away, as would his Army, as the passions subsided. By firing on Sumter, he forced Lincoln to call for volunteers which in turn forced the decisions on the nearly equally divided states of the Upper South. Four went with the Confederacy and four of them remained with the Union, but Virginia was the big prize for Davis.
What he did not account for even though he was warned by his Secretary of State, Robert Toombs, was the near unanimous outrage in the North to the firing on Sumter. It unified public opinion in the North in favor of crushing the rebellion beyond anything Lincoln could have ever accomplished on his own.