Custom is King

Custom, then, is the great guide of human life. It is that principle alone, which renders our experience useful to us, and makes us expect, for the future, a similar train of events with those which have appeared in the past. Without the influence of custom, we should be entirely ignorant of every matter of fact, beyond what is immediately present to the memory and senses.  p.29

To trot out a good ol' fashioned PLS cliche, Custom is King. We saw Herodotus describing one tribe that always ate their dead, and one tribe that always burnt their dead. We saw Gulliver (in the first half of his travels) learning time and again that what seems huge is minuscule, and what seems important is trivial. Here, however, we see Custom coming into the picture in a radically different way...or does it? Herodotus and Gulliver teach us that subjective judgements may be valuable, but should not be taken as Truth. Hume seems to be preaching the same sermon, except he is now applying judgements that were previously associated with morals and rituals to every aspect of understanding. With Hume, we realize that there is every single moment of our lives may be (pardon me for mixing metaphors) like a different island of Gulliver's travels - what we learn from one moment (or island) can not necessarily be brought to the next. However, Custom applying to every understanding is far more radical than the Custom of morals and rituals that Herodotus and Swift present. But, this point could be debated. If we would like to, we can take that as a first question. Judging from what we have read, is it fair to say that, Custom is no longer just King,  but Custom is man's (false) God? By this, I mean that if one assumes that God is a delusion, then God is just an imaginary friend that humans thought up in order to make sense of a world in which things don't actually make sense. It seems to me that Custom, and Cause and Effect serves the same purpose - to provide an explanation of a world that cannot be sufficiently explained, (although Cause and Effect do "appear" to result in concrete betterment of our world.