You forgot the 25 'Go on,make my day!' fleet subs
That's lovely, if they have the new My God, It Actually Works! torpedoes.

(Or they've got about 30 Christ, These Things are Old & Small! boats, which ended up in Britain OTL, which, by terrible oversight,
did have working torpedoes as standard equipment.) It would also help if Cast & Hypo have the latest
Maru Code Decoder Rings from their Crackerjack boxes.
Translation: supplies of Mark X torpedoes, instead of Mark XIV, would have been a huge help. Also, not having a Customs guy in San Francisco be a moron & copy a Japanese merchant (
maru) codebook so clumsily the Japanese couldn't help but notice...

Launch the strikes against southern Formosa on December 8th. The worst that happens is you lose half the bomber force
Absolutely right. Moreover, just preseving the a/c to serve as LR recce could have helped the subs...





Let me put one thing out at the start; the Philippines could NOT be held.
No, the object is to make it as hard as possible. So, a few to add to your list.
Medicine: have it shipped in before the attack. If the P.I. are expected to hold, this would seem simple common sense. It wasn't done.
Ammo: same. A lot of it was no damn good.

And there wasn't enough.
Prepare defensive positions & roadblocks: There weren't any.


Even after Japan said she wasn't going to honor the Treaty

(London or Washington, I can never keep straight which). There weren't even
plans for any.




Nor materials collected.
One of the reasons the Philippines wasn't more heavily fortified in OTL was the Washington Naval Treaty which barred the Americans from fortifying them and the Japanese from fortifying Formosa.
Well, no. It had expired, & Japan had long before 1941 declared she wasn't going to abide by it. Actually, IIRC, it was 1936.
A/c maintenance: add technicians. (There weren't enough of them.) And, hell, at least make sure the fighters' damn machineguns would work at altitude!


(I've read they either clogged from Cosmoline, or froze;

I don't recall which.)
Cryppies :
Evacuate them!!




Christ, which moron thought sending them out as
infantry was a good idea?


ComAsFlt: Fire Hart. His dispositions were
awful. Maybe that's because his ComSubAs, Doyle, was more/less ignorant of Asia (tho apparently Wilkes wasn't...), but hell, couldn't any of them read a damn chart?



Hadn't they heard Lingayen Gulf was the expected landing zone? Didn't they know where Formosa was?
Deploying all six of his Sugar boats in Lingayen Gulf, 10-12 fleet boats in the approaches, & 10-12 off Formosa, Hart might have actually accomplished something. (As godawful as the Mk 14 was, as lousy as prewar training & doctrine were, maybe not a lot...

) They might have gotten a shot at a CV. They could've sunk a few transports. (Jim Coe & Moon Chapple proved that.) If nothing else, they could have boosted morale by
fighting.
Move South:
On Day One, all of Hart's ships, especially
Holland &
Canopus, should have moved to Tawi Tawi. The difference in operating distance to the patrol areas in the SChina Sea was trivial, & it would have forced IJN ASW a/c to work much harder.
Any wrench thrown in the Japanese timetable could only spell crisis pretty soon down the line. The P.I. holding longer could have really buggered the Malaya op. Loss (even due to damage) of even one CV could have tipped the balance at Coral Sea, with knock-ons at Midway.
How much time does it take to realize that MacArthur is a complete imbecile
OTL, it took more than four years of war.



(Very well said, tho.

I wish I'd said that.)