And the fact that Adm Halsey, with all the same information that Adm Kimmel
had stated he intended to shoot down any Japanese aircraft he encountered
and sink any IJN ships that he might find.

Actually Kimmel acted before Halsey and sent 46 ships to open sea without
notifying WAshington in late Nov.

Who countermanded Kimmel's orders and ordered Fleet to return to the base?
Washington (Stark)

Halsey issued his plans AFTER Washington ordered the Fleet back to Pearl Harbor
(His Carriers were part of 46 ship Grand Exercise) as a 25-ship scaled down
version of Kimmels original plan.

But even Halseys scaled down exercise plan was too much for the
Washington,They ordered Halsey to use his carriers to transport planes to Wake
and Midway.
Order came again from Stark.

Why Washington countermanded Kimmels orders and ordered 46-ship fleet to return
to Pearl Harbor as Japanase Task was steaming towards Hawaii?

1)Japanase might abort their mission if they knew US was prepared and waiting
for them.
(That would mean a total failure of McCollum plan)

2)Even if they'd not aborted the mission,PSYOP value of a naval engagement at
open sea would be much less than Pearl Harbor.
Washington knew that if two fleets met at sea and engaged each other there
always might be questions about who attacked first.
(Limited success for McCollum plan,US probably would enter WWII but probably
not so united without shock and awe effect of Pearl Harbor)

Washington had no interest in deterring Japanase or stopping them before they
dropped bombs over HAwaii.

On contrary,Washington wanted to make Task Forces journey between Nov,26 and
Dec,7 as comfortable and easy as possible.
To make it happen they even tried to create a shipping-free zone,so that the
Task force could steam toward Hawaii without worrying about sightings.