I'm not sure we can even judge this far: And so far, none of the gods posited have "come up with" a set of morals worth a hill of beans, at least not in their totality (and frequently in the majority of the rules set forth).
We can only judge morality in the view of what we hold as moral. As you have eloquently said: we are simply too short-sighted to know, It could well be that the morals we dismiss are the morals we need in the long run. As in so much of life we act on faith. We either believe or we do not believe that we are acting in accordance with what is better or worse for (depending on your frame of reference) yourself, others, the world, or what you believe to be objective morality.
In our world trust is impossible to dismiss. We either trust that people have done the research or we do not. We either trust that the road department completed the road over the next hill, or we do not. We either trust that the judge is fair, or we do not. ad infinitim.
I didn't have a chance to address the entirety of this earlier, only one small point. However, here are a couple of things to consider:
1) While we "trust" in most cases, it is possible to check and find out if these things have been done. It may cost effort, time, etc., but it is something which can be done. And when it comes to the research, especially on scientific matters, there is the peer review process as well, which is geared to tear apart anything based on faulty reasoning or reasearch, let alone nonexistent research. This is why, even though faulty articles are published now and again (especially in the popular science media; less often in the peer review journals), they very soon come under attack and are debunked. We saw this with the "studies" which pointed to how harmful vaccinations were; very quickly that doctor's entire structure was taken to pieces, the "research" was shown to be completely without foundation, and even the genuine motivation (a financial benefit) was unearthed. This is why all the furore about "cold fusion" was, at most, a "nine-days' wonder"... it was quickly scrutinized and proven to be, at best, a seriously flawed set of claims. And so forth.
So we can put a reasonable trust in these things; but it never hurts to remember that in science, nothing can be accepted as proven irrevocably; anything in science must be falsifiable, i.e., open to being revised or discarded based on further evidence which casts doubt on or explains in a more thorough fashion whatever model has been held up to that point. This is the great strength of science, as it allows for a constant expansion of knowledge, whereas "absolute certainty" by its very nature places limits on the ability, or even the tendency, to question further. And, whilst some things may indeed be wrong with the model we have (of whatever subject), as Asimov noted, "some things are wronger than others"; these we know flatly contradict all indications from reality, and are thus no longer worth even considering.
2) I don't wish to get into this too deeply, as it would entail going into the religious discussion area, but when one argues that a deity (especially the one most commonly referred to in western societies) had reasons which were superior and beyond our understanding for doing, commanding, or allowing things which we find repugnant and morally reprehensible (genocide, infanticide, etc., etc., etc.), this falls very much in the area of what I mentioned above: special pleading*. In
no other area would we be willing to advance such a flimsy bit of reasoning. If it appears, by any normal standard, to be morally reprehensible, repugnant, and vile, the chances are that it is, without exception, morally reprehensible, repugnant, and vile, no matter from what corner it originates. Most of humanity has learned to recognize this in connection with our despicable treatment of other species, as well as members of other ethnic groups within our own. The actions in question may indeed have had their benefits, but they are nonetheless despicable because they were not necessary to our survival; merely to our momentary expediency or convenience.
And if we're dealing with any form of "supreme being" -- or even a superior being of the Graeco-Roman or other mythologies -- then, if a human mind can conceive of a better, more humane and ethical approach, there is absolutely no excuse for such a being as that posited to be held to any less high standard. It just doesn't hold water without, as noted, completely distorting our ability for rationality into mind-numbing examples of rationalization instead.
HB: I noted the capitalization and what it indicated; but, as I said, there is no reason for choosing any particular deity over any other (evidence for the actual existence of any being rather scarce on the ground); hence the entire concept of it being a single deity tends to indicate an unconscious acceptance of that which has predominated in Western culture for the past millennia and a half; whereas in truth there is as likely to be either a council or at least an enormous variety of possible deities involved (and in such a case, the powers and limitations are widely disparate indeed); hence any morality given by one would still be subjective, as it would be the personal preference of one deity over the others, nothing more. (And, as has been pointed out in numerous instances, even going by biblical accounts, there are indications of many more actual gods than the one generally referred to here in the West.)
The only "objective" morality which could truly be called that is something which is imposed on life by the structure of the universe itself; the very nature of reality. And that can be summed up rather quickly: "Keep your actions to those which truly benefit the survival of your (and perhaps other) species, or you will most certainly die. You may die anyway, but this gives you perhaps a ghost of a chance...."
*along with all the "pretzel-logic" apologetics this tends to entail.
