"Ever since I read it the first time, it has amazed me that MacArthur thought that help was coming."
Help was coming. Many efforts were made. For example, the Pensacola convoy was on it's way and Marshall told MacArthur it was coming. The navy however would not send it on to the Philippines. Additionally, one of the tasks given to MacArthur was to support the navy in raiding the Japanese lines of communications in the South China sea. Now why would one assume the navy wouldn't come to your aid when the navy had a task to carry out?
"That's despite the fact that, beginning the 1934, all of the versions of ORANGE that were discussed and approved by the Joint Board assumed that Guam and the Philippines could not be saved, so they wouldn't even try. And the Chief of Staff of the Army, and head of the Joint Board, when that was approved in 1934, was Douglas MacArthur."
That's because the navy withheld this from MacArthur. They waited until Gen. Embick was appointed head of the AWPD and then told MacArthur that only the navy's lines of communication were being perfected. They said they only changed their initial goal and that the nominal plan had not changed.
"Personally, I think the MacArthur's towering ego demanded (in his own mind) that because he, Douglas MacArthur, was there, the islands must be defended, the fleet must sail to their relief. Anything else was unthinkable."
This isn't right at all. MacArthur wasn't alone in wanting to defend the Philippines. The head of the Philippine Department, General Grunert, was doing everything he could to build it up. Besides, the Army and the government wouldn't have started the rearming of the Philippines just because one person demanded it. It was our duty to protect the Philippines. Really, we had two choices. Either defend the Philippines as our colony or, if you don't want to defend them, grant them independence and leave. The navy failed in this regard as we were not going to abandon our presence in Asia. I agree with Eisenhower, "The trust and friendship of the people of Asia were important to the US; failure might be excused, but never abandonment."
I would recommend reading Prewar Plans and Preparations by Mark Skinner Watson. It gives a great view from the Chief of Staff prior to the war.