Im unsure thats possible. The core of the Embargo Acts was freezing Japanese accounts in the US banks, which was something of a nuclear option in economic terms. Japan had largely moved out of the British banking system in the previous two decade in a effort to gain some independence. How practical it is to transfer the balances to Londons banks & expand credit there I cant say.
OTL Japans port traffic of 1940 was serviced by 11,000,000 GRT of cargo ships. Japan then had just short of six million tons of cargo ships under its flag, the balance being other nations. (From Ellis 'Brute Force') OTL losing the other 5-6 million tons shipping capacity crippled Japan from the start of the embargoes. Exactly how that balance in foreign flagged service is affected by a US/Japan war is a important question. The US would have serious difficulty enforcing a blockade at sea for over a year. The economic model in the British Navigation Certification system my be useful. Whatever the case foreign flagged ships can still get in & out of Japan for a year or more, but the cost/prices will rise significantly. As OTL Japan has a incentive to trade off warship construction for new cargo ships it can operate at lower prices than Greek, Norwegian, or British ships. OTL Japan built between six and eight million tons cargo ships 1940-1944, all of which was sunk 1943-45.
To get to a effective Naval & Economic blockade of Japan would likely require 18+ months for the US.
Its really hard to make a judgement. Unless you have access to Foreign Affairs which has an article outlining In 1941 freezing Japanese USD accounts means only freezing the physical USD in US control so what's in the safe of a US based account holder, bearing in mid that a US USD holder with funds on account in a US based Japanese bank may be exempt and actual trade may be with letters of credit based on the holdings held in Japan itself. Its obviously easier to send a Brinks truck down Wall St to move the money for Japan rather than ship it around the world. ( and even easier to make a ledger entry and keep the USD in a safe at Wells Fargo or Barclays). It also is an asset not a currency value, so the Sumitomo branch building has an asset value but no meaning.
What probably happens is the physical USD reserves are in the Bank of Japan in Tokyo with lesser holdings in other places and lines of credit are extended locally by say Goldman Sachs on the basis that the letter of credit from them to Japan Oil Imports Inc from them is good and they then use that to pay Standard. If GMS is no longer allowed to do that the USD are unaffected and Barings are asked to extend a line so JOIC can buy from Shell.
Any balances not in the US are unaffected and its relatively easy to transfer the line of credit to London, Calcutta, Paris or Frankfurt for that matter. The Banks would have some facilities and contacts particularly in Calcutta for normal business. What becomes harder is to then buy stuff in the US.
I am slightly dubious about the port traffic number I think the definition is sailings per time so a 10Kt ship doing two trips might count at either 20Kt Port traffic or 40 Kt if you count coming AND going. The Japanese estimate was they had 6m t of shipping, needed 3m t for commercial needs and 4m t for the OTL military needs ( or vice versa) which was doable short term. But the bulk of the military movements would have been to DEI, Malaya and the Australian Axis ( PNG, Solomons and Rabaul) which would include substantial volumes for establishing Rabaul) TTL the demand is much less as the bases were established in the 30s.
Its going to be hard for Japan but as long as they have goods to trade and the main ones are silk and fabrics which are to SE Asia they have an economy. OTL ofc the US action was mirrored by the UK and DEI ( and France) TTL thats not automatic at all.
The only thing I have seen on mobilization for War Plan ORANGE is a claim the Army intended to have 50,000 soldiers ready for overseas service in six months and 100,000 in twelve. No indication if that included the entire service support establishment. The Marines were limited by Navy Dept budgets to two standing combined arms brigades in the 1930s & the ability to stand up a third out of active service and reservists, tho it may have been under equipped. So technically a division equivalent. Actually operating a 'division' would not be desirable until USMC strength reached 40,000 or more. Anyway I'd interpret all that as the equivalent of three divisions operational at the twelve month mark. There'd be some supplementary ground and air forces like coast artillery in Hawaii & understrength/undertrained Regular Army & National Guard formation in the US.
Thats feasible but not very relevant. The US army as at 1939 was 175k with 3 full strength divisions ( not exercised as such) and one Cav div plus non divisional and National Guard Units. I think the number includes AAC. I would expect some increase but absent conscription not very much ( OTL it was 1.4m in 1940) with most of the money going on new Aircraft.
The Marines could probably stand up a division in early 43 ( earlier if pushed) the Army is going to have issues. They don't need to mechanise as much but they dont have nearly two years to prepare for mobilisation establish training facilities, induct troops and do the whole mobilisation thing. That takes everyone about two years. So starting from 44 yes. Before that some things will be available but target 1 will not be an island in fighter ferry range of a protected base with a functional air warning system provided by the Aussie coastwatchers. Its going to an Island (Makin, Tarawa wherever) a couple of thousand miles from your forward base and in range of air attack with no practical warning by the IJN. The US can probably take it but to hold it they have run convoys on fairly predictable routes in low fuel states at the wrong end just to provide water for the garrison with the last part being in range of IJN land based air and without Midway an equal of superior carrier force able to ambush you until the main tranche of Essex come out in late 44, well in time for Dewey to claim the credit for final Victory, unless FDR capitulates.
The US blockade is not really feasible until you establish a patrol line from Pearl or Midway (Australia being Neutral) and distinguish between trade with Japan and any other trade - that tend to push the patrol line North but there re lot of neutrals around.
