The fact that Kirkgegard is being cited proves this is philosophizing, not halaha.
As verified by Rabbi Moshe Weiner (author of The Divine Code), Noahides may light Hanukkah candles, but without reciting any of the associated Jewish blessings. For Gentiles, those would be false statements said in God’s Name because they testify that the person lighting the candles is commanded to kindle the lights of Hanukkah, and that God did those miracles for “our fathers”, both of which apply only to Jews.
Rambam's ruling in Laws of Kings 10:10 has nothing to do with spiritual perfection. It talks about a practical benefit. For example, to marry a woman only to refine himself, to return some lost objects and so on.