I like Lincoln. Thought he was a good tough politician. Because I admire his politicial skills, I do not tie myself up in the knots you do trying to justify what he did at Ft. Sumter. You can't have it both ways. He can't be the smart politician he was and be surprised at what happened at Sumter. The two don't mesh. Actually I think they do. If you read his speeches leading up to and including the Inaugural address he made clear his intention to retain ownership of federal property. Having done so in such a public manner he somewhat painted himself into a corner. He had little choice but to resupply Sumter, and probably hoped to do so peacefully.
You can't argue history like that because now your argument doesn't take into account the South as a player in the conflict. The only agent in your construct is Lincoln. What he wants. No conflict can be understood under that type of constricting historiography. One side was not passive while the other was active. Both were there shaping the events.
Lincoln knew that if he sailed into the harbor, he would get a war. He knew it. That knowledge must be evaluated in his actions as well.