a few things
The US Army is in charge of coastal defenses, including coastal minefields but there is a gray area here, in that the Harbor Defense Command did not have the resources to put more then a few guns for the entire Lingayen Coast. I am not sure (although research is ongoing) how many mines the Army or Navy had available, but I have no indication that anyone ever even broached the idea which leads me to wonder if it was due to lack of resources or lack of imagination. As Lingayen Gulf was expected to be the principal invasion site going back to the turn of the century when the US Army first started developing defense plans either is a biting indictment.
Remember, Krueger, recent commander of the 3rd Army, is the commander of US Army Forces Far East, and Eisenhower is his Chief of Staff, thus Krueger's subordinate. Although a highly connected one (in terms of the Filipinos with clout) and with the respect of General Marshall.
To be fair in my last timeline involving the Pacific War were Macarthur appeared (Gorings Reich) I had him relieved for cause for criticizing FDR in public. In this one I consider him one of the problems the US Army had, but not the only problem it had. During the campaign there were a couple of occasions when he very well could have been killed by a stray Japanese bomb, not to mention the possibilities of disaster during his evacuation, so killing Douglas is not hard to do in any timeline.
As to radar, the US Army did have an operational set at Iba Field. It and its operators were destroyed on the first day. Japanese intelligence work leading up to the invasion was superb as far as to what the Americans had available. Their major mistake was in not realizing the size of the defense force at Bataan or that the retreat there was planned for decades.
As to the Philippine Air Force as well as the flow of the campaign I will be posting on that pretty soon (this weekend)
Thank you for all the kind wishes, they are appreciated. Chronic recurring illness is tough on everyone involved.