Here's where some politicians should object; military officers should NOT be making political policy. Seizing land from property owners is a political decision, not a military one. While the Radicals may agree with Sherman's order, they should remind him that he cannot issue such an order as it infringes on the powers of the civilian government. IOTL, early in the war, Lincoln relieved Fremont of his Missouri command because he was freeing slaves of Union loyalists without government approval. If the Radicals want to redistribute land, that should be a part of postwar Reconstruction.
That makes sense; concentrate on winning the war first, that way the Radicals will not be able to use the War as an excuse for drastic actions.
Why? If anything, an earlier seizure of the Fort would have helped the National Unionists immensely. Remember you don't need to take the city; capture Fort Fisher and the port is sealed off.
True, but Radical behavior could make it more difficult to settle issues like the
Alabama Claims.
Not likely; the Fort and other batteries had Whitworth rifled cannons with a range of five miles. Also the Confederates laid mines on the landward side; the Union warships would have to get in close to bombard the landward defenses and destroy the minefields. It should be noted the ships will not take a lot of fire; Lamb had to conserve his limited ammunition for the ground assault.
BTW
here's an article on the history of Fort Fisher.