Since you clearly believe that every religion is man-made, your argument unfortunately collapses upon itself. If religion is intellectually bizarre, then, by definition so is its creator. And since you claim perfection is a category error, I’d make the claim that the term bizarre is entirely subjective. And, by the way, tell the engineers trying to make telescopic lenses for satellites such as the Hubble that there is no such thing as perfection… they work tirelessly toward it to ensure the best performance possible. The reverse of which is a plague of quantifiable inefficiency, not merely a category.
To your second claim that religion is a powerful source for legitimizing really sinister stuff… that is pretty much true of any of mankind’s big think adversarial worldviews. Do you claim that the antireligious Nazis, Soviets, and Maoists got it right? I’d argue that they were pretty sinister and they were, by and large, not particularly religious.
Third, religions in general, are no better or worse as a source of meaning. Are you suggesting workaholism, nihilism, and consumerism hold the key to humanity’s meaning? Rather I’d argue that worldviews that emphasize serving and sacrificing for your fellow humans are a great place to start. We cannot flourish in isolation and I’d argue that humanity’s downfall starts with an unnecessary splintering into adversarial groups. Of course we will have differences, but if we truly serve one another, there will be much more to bind than to divide.
As far as the issue of happiness being of secondary importance in religion… any 101 psychology class can teach us that happiness is ephemeral and fleeting. That is not where we should be putting our effort at life’s meaning. So it’s probably a good thing that it is of secondary value. If only, though, that were actually a secondary pursuit. How the world would be different for the much, much better!
Lastly, I absolutely agree with you that the world should avoid worshipping groups. The world’s darkest hours are defined by one group, or another, trying to destroy another group. Let us be wary of isolated or adversarial groups and unite in common cause to serve one another selflessly. Now that is a worldview, or religion, or whatever you want to call it, worthy of our time, effort, and investment.