WHAT exactly is wrong with dating a cousin or any non-direct family member?

I've been researching dating cousins, second cousins, cousins once removed etc on Y!A because I particulary like my first cousin once removed (my cousin's son) and I can't believe how many people think it's "just wrong" for no reason at all

1. "Your kids will be messed up!" Studies have shown that it's a whopping 2% that children with related parents will have a deformity than those non-related. And thats usually only if you both have a bad recessive gene, you can have doctors do tests. You're more likely to have a baby with down syndrome just by having one in you're forties than with a not so close relative. And as we know, ALL couples who date are ALWAYS going to have children.

2. "You'll be ostracized!" The easy solution is to not walk around wearing a t-shirt that says "I'm dating my cousin!" People won't have to know if you don't tell them.

3. "It's wrong to date someone you grew up with!" Some family members don't even meet until their adults. They can fall in love just like anyone else. They're people to.

4. "It's illegal!" In some states yes, and in some states it's only just first cousins. However some of these laws are starting to be lifted. It's not illegal everywhere, and it's encouraged in some cultures.

5. Albert Einstein and Charles Darwin married their cousins, and people think of them as geniuses, not sickos.

6. "Leviticus says its wrong!" Then why else did so many people in the Bible do this anyway? And not everyone is religious.

7. "Eww incest is gross!" Au contraire, incest is considered sexual relations of direct family members, parent-child, siblings, granparents, etc.

8. About 20% of world marriages are between cousins. I don't think we live in a 20% retard world.

And no, I'm not from Alabama, West Virginia, or Tennesee. So can anyone please give a good reason why this is so immoral and gross?