I think you make many excellent points.
I also think that there were ways to minimize the wholesale, comprehensive nature of the "surprise" attack without much risk to the things you mention.
The forward observation posts and the communications between key personnel could have been . . . heightened and given some contingency procedures to lessen the damage without appearing to have known about it all more than 1-3 hours beforehand.
Foreign fishing boats could have been strung loosely across the probable path 2-3 hours out--or--better--a few subs. Might have been suicidal duty but still less devastating than what happened.
Maybe what I'm suggesting is more unreasonable than I think. But what's wrong with setting up a Pearl Harbor Lite vs what happened? It would have still been sufficient to compel the populace into the war.
During Viet Nam . . . well after . . . McNamara, then SECDEF whined that we
ONLY had 50,000 casualties/deaths. They were hoping for more and certainly now knew how to insure many more the next time.
THAT'S the mentality running things. They still are.
Individuals, lives, families, life is merely to be manipulated and trashed at will by the elites as their just due and right--whether for sadistic fun; for geopolitical rearrangements; strategic advantage or merely to sacrificially please satan in some horrific ceremony a la "Spirit Cooking" and Pizzagate.
WWII was set-up to further their globalist goals from the beginning in both Europe and the Pacific. They succeeded.
That Pearl Harbor played such a calculated yet horrific role early on is merely history. But it is a sobering history about the evils of the PTB and their willingness, eagerness to destroy lives to achieve their global goals.
IIRC, I've read convincing testimony that FDR committed suicide. Aids reported he called for a loaded pistol to be brought to him etc. Small wonder. Brain hemorrhage, indeed. A bullet through the skull tends to foster that.
Every WWII movie I've seen that involved Pearl Harbor, at all . . . has always left me feeling great angst to some level of outrage.
I don't know that I have a lot of brilliant answers. And I know that God has all things in His big hands.
And I know that the USA was set-up by Him for at least a couple of major reasons:
1. To spread The Gospel.
2. To help establish and initially protect Israel . . . and likely
3. To demonstrate to all Creation that even the most ideal form of government will turn utterly devilishly evil apart from an intimate walk with the God of Abraham, Isaac and Jacob.
@Quix
Let's, for a moment, suppose that FDR had the definitive skinny on where, when the attack was to take place, that he even had a general idea where the Japanese attacking forces would be located and flying from/to.
Okay, then what?
Had there been a preemptive strike, the Japanese would have casus belli and America would have been the aggressor, in the wrong for attacking those Japanese warships just peacefully steaming around conducting practice air operations.
Would the American people have followed Roosevelt into war under those circumstances?
Now, it gets tricky. Suppose he knew, and then American ships launched a counterattack as soon as word came that the attack was in progress from carriers already at sea and near the Japanese force. That would have tipped his hand, and possibly exposed the entire Kabuki by showing the American people that the attack was known about in advance, and nothing done to intercept it (see above).
It would have, again, short of collusion on the part of those in two opposing governments soon to be enemies, tipped the Japanese that we had, in fact broken their codes, which would have caused them to change them, leaving the US at a relative intel deficit at the beginning of what would be a protracted conflict.
This raises the killer question: Given that we knew, what major action, if any, could the US take without giving away that we were reading their encrypted messages?
A casual sortie by the carriers moved ships key to the coming conflict out of harm's way, an odd situation, because the common strategic and tactical thought in the USN of the day focused on Battleships, and not the extraordinary projection of attack power later proven inherent in a carrier navy and naval air power. It was Pearl Harbor that proved the might of the Carrier Task Force above and beyond the Battleship. What we now see as obvious was not so much so back when.
So, I must ask, what would have been done differently had the Commanders at Pearl Harbor known?