First of all

I also think that religion as a whole is worth the genocides, wars and witch hunts that sprouted from it, because of the sciences and curiosity that it drove.

That's a bold statement. I like bold statements, I like people who make bold statements. I politely disagree, but that's not the point. Now to the meat of my response.

"And all that have not fins and scales in the seas, and in the rivers, of all that move in the waters, and of any living thing which is in the waters, they shall be an abomination unto you:"

This basically says don't eat shellfish. Back when the early Hebrews were putzing around, there's evidence to suggest that red tides were a bit more common than they are today. And that's bad for shellfish, and really bad for anything that eats shellfish. You have figured out that sometimes, when people eat clams, shrimp, crabs, etc, they get really sick and die. So, in order to keep the faithful alive, and to keep your religion prominent (Basically the same thing, the Canaanites were only one of the various religious warbands running around that area of the world), you need to make it harder for people to kill themselves. And because you don't have the ability to diagnose illness all that well, or even realize that it's a natural poison/toxin rather than divine wrath, because some people eat this stuff sometimes and are just fine, you have to make it a crime against your god to eat this stuff. Because you're going to need that imbecile who eats toxic food to bash some non-believers head in, and to make more believers.

This, combined with the organizational structure and preservation of knowledge that the Catholic Church (Really the Jesuits) preserved in a period of relative anarchy, are really the only demonstrations of value that I see in Western religion. (Eastern having a lot of the same pluses and minuses, but I'm not as well versed in their histories and relative examples.)