H.H. Hoppe, a libertarian, grasped one, most materialistic reason for monarchy. The other reason is the role of a monarch as an embodiment of the national idea. For example, a monarch may see a national goal in fostering local government and democratic self-government, -- things that America understands and longs for intuitively, but contradict the selfish instinct of anyone in the actual business of governing. That is to say, while the governemnt -- feudal or democratic -- is in the business of governing, the monarch is in the business of recognizing and further shaping the national identity. Even the degenerate monarchies of today, such as the House of Windsor, work as a surrogate national parent. Note how the personal developments in the British monarchy come to matter something rather intangible but at the same time something very important to all Britons. American presidents fill a similar role out of necessity: Reagan morning the Challenger or egging on Gorbachev in Berlin, Clinton in Oklahoma City, W. Bush on the rubble of 9/11, -- but they are not well suited for it, because every time there is a 40% or more who listen to that and say "damn, that improves the bastard's ratings".
When American presidential candidate says "I want to be a president for all Americans" -- and they all do -- he is speaking nonsense. I am an American: I don't want to be for 4 years trying to move myself as far left as I can and in another 4 years moving myself as far right as I can, but these are the rational political goals of a President. Of course, the candidate does not mean that; what he means is "I want to be a king of America". But the truth is, he cannot be a king, that is why in 2 years he is back on the tube selling us more of his government at our expense. One cannot be a father figure one day and hustling an election the next.
Of course what you say makes a lot of sense. As you know, the Presidency as originally conceived by the Founders was not what has developed. He was to have been a quasi-monarch, chosen every four years by a select group of non-partisan electors whose only concern was what was best for the country. The person chosen (theoretically without his knowledge) would then be asked if he accepted the office. It sounds like Alexander Hamilton, whom some conservatives consider the father of the "eastern liberal establishment" and "the money power," wasn't so far off after all!
However, there are also elements of your answer that I find troubling and indicative generally of the weaknesses of "palaeoconservatism" (please forgive my use of the term, as I am not sure it applies to you at all). The idea of a slowly developing, "organic" worldview seems to me tainted with henotheism, relativism, and utilitarianism. It implies that there is a different (and equally valid) "truth" for each people. The idea of a slow development through trial and error is also highly utilitarian (as well as organic). As a Biblical Fundamentalist I believe that there is One G-d and One Truth for the entire universe. The particular characteristics of all the various nations are fine of course, provided they acknowledge and submit to this One Truth. I also believe that G-d has provided the human race (in the Noachide Laws) THE laws for living, and no long, organic, trial-and-error development is necessary. Perhaps this is where some "palaeos" see the Jews as the ultimate source of the left's "rationalist blueprints" for human life; for what is the Torah if not G-d's own "rationalist blueprint?"
It is most strange that so many conservatives castigate the idea of a "one world religion," when all orthodox believers (at least in the "western" tradition) who believe their religion is the true one ipso facto believe in a "one world religion" (theirs, of course). I sometimes wonder if the hoo-haw over "one world religion" doesn't have roots in henotheism. Don't get me wrong, though. I am adamantly opposed to any "one world religion" other than the True one.
Pinging wideawake for his interest.