There is absolutely no way the Philippines were going to get out of being occupied.
Their geographic location was too dangerous to Japanese interests to be allowed to be under any other authority than Imperial Japan.
I am sorry to come back to this so belatedly but I found it quite difficult to investigate. One problem is that after "The war situation has developed not necessarily to Japan's advantage", it was hard to find people who might have admitted that they had been strong advocates of the Pearl Harbor attack. However, I am fairly confident that the Pearl Harbor operation was supported by very few Japanese officers, essentially Admiral Yamamoto and some of the Combined Fleet. Even Rear-Admiral Onishi Takijiro, who was one of the planners argued "...we should avoid anything like the Hawaiian operation that would put America's back up too badly" according to "The Reluctant Admiral: Yamamoto and the Imperial Navy" by Agawa Hiroyuki, page 229. Onishi's views are also given in Prange's "At Dawn we Sleep" on page 261 where he is said to have argued that "If Japan confined its push to the southern regions, even including the Philippines, the Americans would be angry, would even fight, but would remain open to negotiations. However, if it attacked Pearl Harbor, that would make the United States so insanely mad that any hope for a compromise peace would go up in flames." Nevertheless, Yamamoto forced his plan through by offering his resignation and his superior, Admiral Nagano Osami, gave up his objections.
The difficult question is who supported an attack on the Philippines and who preferred the gamble of ignoring the Philippines to the gamble of fighting the USA. Vice Admiral Kondo Nobutake, initially Nagano's vice-chief of staff and later commander of the 2nd Fleet under Yamamoto, maintained that Japan should attack Malaya and the Dutch East Indies only according to Prange pages 284-5. Similarly the Navy Minister, Shimada Shigetaro, is reported by Fukudome Shigeru to have opposed attacking America (The Japanese Navy in World War II, ed. David C. Evans, page 6). His predecessor as Navy Minister, Oikawa Koshiro, had been asked by War Minister Tojo Hideki about the prospects for victory against the United States and had replied he was not confident the United States could be defeated.
The most senior officer in the Navy, with the right of access to the Emperor, was Admiral Nagano Osami and, sadly, his views are hardest to understand. The Battle of Midway by Craig L. Symonds, page 91 has:
The first open split between Nagano and Yamamoto came over the wisdom of striking at Pearl Harbor. Nagano believed that it would be possible to seize the British and Dutch possessions in the South Pacific without drawing the United States into the war. He argued that the Pearl Harbor gambit was unnecessary and risky, and that it would pull resources away from the all-important strike southward. Yamamoto saw this as timidity. He opined to an associate that Nagano was "the kind of man who thinks he's a genius, even though he's not," and told another, "Nagano's a dead loss."
Similarly, "The Shattered Sword" by Jonathan Parshall and Anthony Tully says on page 24 that the Chief of the General Staff, Nagano Osami, did not wish to attack America.
Louis Morton's "Japan's Decision for War" has "There was only enough oil, Admiral Osami Nagano told the Emperor, to maintain the fleet under war conditions for one and a half years and he was doubtful that Japan could win a "sweeping victory" in that time. His advice, therefore, was to drop the Tripartite Pact and reach agreement with the United States."
I found some more quotes in "War Leadership Concept before the Greater East Asia War: Aftermath of the Imperial National Defense Policy" by Taeru Kurono:
1. On July 31, 1941, upon inquiry by the Emperor concerning the possible war against the United States, Osami Nagano, Chief of the Naval General Staff, replied to the throne that it was doubtful whether Japan could win, not to speak of achieving a great victory as won in the Battle of the Sea of Japan, and if it prolonged, he "had no idea about the consequences," and the Emperor entertained the impression that "how dare we start a war with no prospects of victory."
2. On November 4 1941, Nagano stated, "I am certain that the Imperial Japanese Navy will be victorious for the first two years, but I cannot foresee what will happen if the war becomes prolonged because the future holds various uncertain factors."
3. However, on July 21, Nagano announced that Japan should decide to start the war against the United States promptly because the differences in the military strength of Japan and the United States would enlarge as time passed (Sawamoto Yorio's Diary, entry on July 21, 1941).
There is a biography written with the help of his family called "He Gave the Order: The Life and Times of Admiral Osami Nagano" by F.J. Bradley. I spent a fair time reading the bits available on Google Books and I learnt a good deal about his wives, all four of them as they were unlucky in childbirth, and nothing about IJN policy. However, there may be something on the hidden pages.
Louis Morton's "Japan's Decision for War" is available on the internet and here is a long quote from chapter 4, pages 105-6, which talks about "the Navy" without saying who represented the Navy:
"By the middle of August the two services had agreed on a broad line of strategy. The impetus came from a series of studies presented by the Total War Research Institute, a subordinate body of the Planning Board. Forecasting the course of events during the next six months, the Institute called for the invasion of the Netherlands Indies in November, followed the next month by surprise attacks on British and American possessions in the Far East. Anticipating that the United States and Great Britain would utilize Soviet bases in a war against Japan, the Institute's studies dealt with the problems of economic mobilization; military planning, except in the most general sense, was left to the services.
These studies, as well as others, were discussed heatedly during the tense days that followed the embargo. From these discussions emerged four alternative lines of strategy, all of them designed to accomplish the swift destruction of Allied forces in the Far last and the early seizure of the Netherlands Indies. The first was based on the Institute's studies and provided for the seizure of the Indies and then of the Philippines and Malaya. The second called for a step-by-step advance from the Philippines to Borneo, Java, Sumatra, and Malaya. The reverse, from Malaya to the Philippines, constituted a third line of action and one which would have the advantage of delaying attack against American territory. The fourth plan proposed at this time consisted of simultaneous attacks against the Philippines and Malaya followed by a rapid advance along both axes to the Indies. Admiral Yamamoto's plan for an attack against Pearl Harbor, work on which had begun in January, did not enter into the calculations of the planners at this time.
Army and Navy planners agreed that the first plan was too risky for it would leave Japanese forces exposed to attack from the Philippines and Malaya. The Navy preferred the second plan; it was safe, provided for a step-by-step advance, and created no serious problems. The Army objected to it, however, on the ground that by the time the main objectives in the Netherlands Indies and Malaya were reached the Allies would have had time to strengthen their defenses. The third plan, with its early seizure of Malaya and bypassing of the Philippines, appealed greatly to the Army planners who hoped in this way to gain southeast Asia and delay American entry into the war. But this course, as the Navy pointed out, also placed American naval and air forces in the Philippines in a strategic position athwart Japan's line of communication and constituted a risk of the utmost magnitude. The fourth course, simultaneous attacks and advance along two axes, created serious problems of co-ordination and timing and a dangerous dispersion of forces. But because it was the only course which compromised the views of both groups, it was finally adopted."