Yes. Its disgusting and wrong.

I don't see why not. Studies have shown that close relatives release pheromones that put them off from each-other. For some people this must not be the case. And for a subset of those they find themselves in love with their close-relative. With the diversity of populations today, due to movement, the genetic risks are also lower (only slightly) because people have much more vigor genetic backgrounds.

Now should we support socially two siblings or other similar relations having children? Of course not, but in the same way we don't support a woman drinking while she is pregnant. We don't outlaw it, but we make it clear to them that there are risks involved, and they will be responsible for the consequences (taking care of a mentally deficient child, for example.) Maybe they could consider fertilizing somebody else and raising the child as their own? Or adoption? Eventually with in-vitro fertilization and increasing skill in genetic techonology doctors will be able to choose which fertilized eggs are safe.

Hehehe..
Kentucky allows marrying are cousins,
but incest,
ehh?

Isn't marrying cousins and sleeping with them still considered incestral?

Morally wrong? No. It's two consenting adults. What if you had a bro/sis that you were separated from because you were adopted, and you met later in life and boned. Would it be "wrong" if you didn't have those familial ties ingrained into you? I get that argument from the idea of banging a hot stepsister: we ain't blood, and what if we met each other before our parents married? Then we would be "related". You can't pick and choose in this scenario (having a "sister" that you always know as a sister and saying it's "wrong", blood related or not, but then say it wouldn't be wrong if you simply didn't know each other).

I, personally, think that shit is weird and I wouldn't do it. I'll think you're weird for it, but hey man, do what you do.

Now, is it "biologically wrong"? Yes. It fucks up gene pools (it's why cheetahs are kinda screwed right now) and has a higher chance of producing children with severe disabilities, which means they'll have a low quality of life and your own quality of life will be lowered (I guess the "quality of life" question could also be a moral one, but I wanna focus on the biological issues that arise). Joffrey was a shithead, fyi. But for real, there are some very real negative consequences to it.

In terms of doing a relative, how close we talking? Sibling? Cousin? 2nd cousin? On the moral question, it's all the same, but on the biological question, the closer the relative gets to you, the worse it is. 

Likely wrong, because siblings who meet each other only when they are older actually are more likely to be attracted to each other. It's called genetic sexual attraction. Not to mention it has been strongly suggested people choose faces and smells most closely ressembling their parents' or their own in a partner. Maybe you are mixing it up with the Westermarck effect? Which has nothing to do with pheromones, but merely being raised together from ages 0-6 (blood relatives or not).

Yeah

Specialy the lannisters

Ehh its legal here so no worries.

Where is "here"?