Couldn't disseminate the news that fast. Frex, most likely some members of the Arizona's crew didn't even know a war was on when they died, especially those in the Black Gang.
Allow for the fact that most BBs only had one boiler lit that morning. The only reason the Nevada could make her famous run for the open sea was because the acting chief engineer had kept an extra boiler lit (against protocols) so he could do the switchover later that morning. Also, ALL the ships in harbor suffered from having too many crew members ashore.
Once a Battleships alarm goes off what crew she has on board will close up at action stations - 5 minutes should be enough for the duty crew to close all doors and man the Lighter AAA
1 Hour would have all the ships weapons systems on line and manned
My understanding is that it would take roughly 4 hours for a battleship to get steam up in her boilers in order to start manoeuvring effectively
That's primarily why I chose 1 and 4 hours
For those quartered near their planes...

But it won't make much difference, other than perhaps more pilots killed on the tarmac.

Maybe but more US planes in the air = far more difficulty in the attacking IJN waves forming up and making a proper attack run.
Its a harsh reality but Planes and pilots can be replaced much quicker than battleships!
Actually, if Kimmel absolutely hits the panic button, and the rest of the BBs' captains, divisional commanders, and the Battle Force Commander himself (Pye) are willing to work as hard and fast as the Nevada's crew did, you could have the dilemma of a "crowding effect" of major warships trying to leave at nearly the same time. "Everyone storms the exits in the burning theater and no one gets out"?
The USN was a professional old school organisation that was about 150 years old in 1941 (if we accept 1797 as the true date of the USNs creation) - personally I would give them a bit more credit than that
The Nevada makes it out no question though. And the NV proved something under fire that had long been argued about in Pearl Harbor...A battleship CAN get underway, leave dockside, maneuver through the Inner Harbor, and presumably the Outer Harbor and Outer Channel WITHOUT the aid of tugboats.
Getting the bombers and PBYs dispersed that quickly might be a problem in terms of getting them airborne. But if it can be done, they can go to the other islands for cover. Getting the bombers "bombed up" will take too long at Four Hours (penetrating disbelief and rounding up essential personnel in a "peacetime environment" is very hard).
Again Professional Navy's had been in the business of getting crews back to ships from shore leave etc ASAP since before the USNs creation.
The ships could sortie once they had sufficient crew (or enough to move)
This will depend a lot on US Army/Navy cooperation

, as with Four Hours Warning
the Opana Point radar station will not only remain manned and operating, but even under possible heavy guard. So no "Instant tactical surprise" ITTL. Which leads me to...
At 4 hours tactical warning and the USN knowing that the Japanese were coming and that they were unlikely to have all the ships out to sea then the goal posts have changed - would the NV be trying to run for the open seas on her own or would all the fleet batten down the hatches and fight it out from the harbour?
That's what Harbor Masters are for. To throw up the Red Flag the moment the Opana Point radar installation tells the navy of the approaching Japanese attack waves and roughly when they could be expected to show up. So they would have "X amount" of time before throwing down the bar. This happened when the Nevada was turning towards the Outer Channel. The Harbor Master Station had the flags up closing the harbor. The NV's skipper agreed with the Master's decision and beached his ship, but there were more than a few angry junior officers who thought that the order was wrong.
But as you say, it wasn't.
Again 'Professional Navy' - the Skipper knew the Risks and acted correctly
True, on an individual basis. But its not like they were the crews of the Repulse and Prince of Wales, sailing off to their doom. Or even the Bismarck's, who at least had the prospect of rescue by the British, and could have had a lot more survivors if an offensively disarmed U-Boat hadn't foolishly closed in, forcing the heavy cruiser Dorestshire to abandon the German sailors to their fate. A handful were rescued by the U-Boat, but that was all.
A ship suffering a magazine explosion or rapidly capsizing could still take a sizeable chunk of her crew with her
At Hawaii the Standards would be operating in friendly controlled waters and skies, in calm seas, warm water, and few (if any?) sharks. I say friendly skies because the Nagumo Force will have little time to tarry and strafe helpless sailors bobbling in the water. Not that they wouldn't if they got the chance.
Granted those that went into the water would probably last for a lot longer than some one in the North Atlantic or Arctic ocean
Meh. Short's "7th Air Force" on 12/7/41 was as deadly as a kitten to targets at sea. I'd barely give them credit to handle supporting tactical operations defeating a Japanese invasion force (ASB), but the mass obsolescence of so many of their aircraft (B-18s, P-35s, P-36s, Buffaloes), or unsuitability for naval air strikes of others [B-17s, A-20s[size=-4](bomb load)[/size]], renders the entire body of aircraft on Oahu useless for any missions except diversion, recon, or CAP. And the CAP mission mainly due to her complement of P-40s.
Any of those fighter planes are a threat to the IJN Strike aircraft - they might not be able to match Zeros 1 : 1 but WW2 is full of examples where the lesser Aircraft triumphed.
And as I pointed out its the Strike planes that will suffer not the Zeros
Basically if a first wave did still attack and the USAAF managed to launch a major fighter effort then there is not going to be a 2nd wave and the losses suffered is going to be much greater than OTL
I know some may point to the aircraft shot down by some of these iron coffins (NOT the P-40s) at Pearl OTL. BUT: The Japanese had never done anything like this. In some ways, even their vaunted veterans were "newbies". And they too made newbie mistakes. Since mostly only squadron and flight leaders had radios, once the fighters broke formation to hunt targets (seeing no aircraft in the skies), their commanders lost the ability to recall their planes quickly enough to deal with immediate threats, like a few fighters being able to take off and engage the enemy. An enemy who had grown complacent, thinking that there were no enemy planes aloft at all.
So when the Nevada made her run, there was no way for the Japanese to "call in the clans" from the moment she pulled away from the dock. So too when the handful of American fighters that got off the ground engaged the enemy, some could enjoy an initial level of surprise, especially the famous two pilots from the auxiliary field at Haleiwa. But then, they were flying P-40s.
...and at this time the Americans know NOTHING about the Zero, much less how to combat it. When they try to engage a bunch of "near-sighted pilots flying tinker-toys"
Again while this would result in many losses among the USAAF fighter pilots and planes it would correspond to higher losses among the Dive and Torpedo bombers of the first wave and fewer Battleship losses.
And as I some what callously pointed out Fighter planes and Pilots are easier for the US to replace than Battelships
Yeah, even the beach defenses are manned at this point.
The Standards lack the speed to catch up to Nagumo and Nagumo lacks the fuel to hunt for them. If Nagumo tries for a Third Wave, some of his DDs aren't getting home. If he stays through 12/8, NONE of them are. And since he doesn't know that the vaunted Mark XIV is fractionally less dangerous than a barrage of spitballs...

, he could in his own mind be facing a "Night of the Long Knives" before he ever gets home. IF he gets home. If there was one thing the world's navies had learned to appreciate, it was the power of the Submarine.
I doubt seriously that Kimmel would go that far. If he does, its only because he lacks the fuel and escorts to cover the Standards.
And yes, CAP is the One Thing I could trust Short's boys to pull off.
Yes I would expect the Standards + Cruisers and DDs to move south east and await the carriers - I dont think the US Admirals would try chasing the IJN ships unless they new where they were etc then maybe they might give it a stab (the Cruisers and DDs might very well catch the Jap Flat tops)
IDK about that. AIUI, the barber didn't even know who he was talking to. Its not a matter of making sure there is no one to answer the phone as it is to insure the person on the other end of the line is not able to make the call in the first place.
To shut down the Japanese intelligence operations to affect Japan's knowledge of the fleet sortieing, you'd need to storm or otherwise shut down the Japanese Consular Office from the outside world almost immediately. Then there's the issue of the Japanese submarines in the area, especially the midgets, who were giving vital intel to the IJN right up until 0400 on 12/7.
I was making a wry observation using the Japanese barber telephone Scene from the Film Tora Tora Tora to set a scene in the readers head
And who knows maybe the POD is that US Intel has totally broken the Japanese network?