The point of the invading the Dutch East Indies, was to gain the resources to continue the second Sino-Japanese War. Can we agree on that point?
Sure, tho the US and Britain freezing Japanese bank accounts and credit pretty well forced Japans hand. The embargos covered the entire Japanese import export economy. Through 1940 & into early 1941 over 40% of Japans port traffic was carried in foreign flagged ships. The embargos left Japan with a massive cargo shipping shortage. Even if it obtains acess to the Indonesian oil the 40 odd lomg distance tankers Japan possesed were wholly inadaquate for the task.
Japan had to force the US & Britian to lift the embargos. Otherwise it faced the near impossible task of creating a autarky within its empire.
Can we also agree that the American public prior to the attack on Pearl Harbor were not motivated to go to war, that it took the attack on U.S. forces in Pearl Harbor in order to "wake the sleeping giant" (even if FDR wanted to move the nation towards war on the side of the Allies)?
No, not at all. The US Congress had already passed the War Powers Acts in 1940. The National Guard had been taken into active Federal service, the Army and Navy reserve officers had been mobilized into active service. Congress had handed blank checks to the War Department and Navy. Massive construction programs were under way for a modern army of 100+ divisions & over 50 air wings. Two new classes of battleships were under construction along with literally hundreds of other warships & support ships. The US was already reinforcing the Phillipines, preparing to construct fortresses on Wake & Midway island, and conducting war planning with the Dutch and British. The last included sharing intelligence all three were gathering.
If a nominally neutral Dutch Empire continued to trade with all nations, including the Empire of Japan, how would the United States stop this trade?
As in my replies above, the embargos went way deeper than cutting Japan off from Texas crude, or scrap steel. To keep the war in China financed, or provide capitol for its empires industry to grow Japan was wedded to the New York and London banks. Even if the credit had not been cut off and the accounts not frozen, there was still the problem of the Brits controling the cargo ships. At that point the Norweigian, Dutch, Greek cargo fleets were under the control of the exiled governments sitting in London. The Vichy French had no incentive to service Japans cargo needs since the Japanese were in the process of stealing Indo China from France. The Italian & German cargo fleets were trapped & unusable for Japan. Simply between the finance freeze and the cargo fleets withdrawn from the Japanese trade Japans economy was in free fall in the latter half of 1941. So to answer the question directly, the US and Britian had already effectively stopped Japans trade in the summer/autum of 1941.