Nudity is natural. I really don't see what's wrong with it and why people make such a big fuss over people being able to view certain body parts in public. It's probably a cultural thing we inherited from the Europeans. Peoples native to warmer climates frequently lived without clothes and their societies were not affected by any sort of mass degradation of morality as some would have you believe is the natural result of seeing such body parts.

You're right, nudity really has nothing to do with sex, but it is equated with sex in our culture because sex is one of the few times people ever see anyone else naked. In societies that developed without clothes, for instance, the female breast is not typically viewed as sexual. But here everybody gets in an uproar when a female nipple is visible at the Superbowl, as if it had some sort of potential to cause any harm to anyone more than a man's nipple could (which seems like a pretty sexist idea to me).

It's usually religious Christian moralists who rigorously oppose nudity in public, in the media, and yes, even in art. These are people who are motivated by the idea that anything remotely related to sex (even nudity, which is only associated with sex because we hardly ever see nude people outside of sexual situations anymore) as sinful and wicked and against God's will and so forth, and they wish to impose their religious viewpoint on the rest of society.

To answer your questions:
No, nudity is not socially acceptable, but in an ideal society it would be.

I hang around my room naked sometimes, but other than that I rarely get to be nude due to social stigmas and the highly successful campaign of the aforementioned Christian moralists which makes it a crime (!) for me to show parts of myself their religion doesn't like. Which change over time, by the way. A hundred years ago it was taboo to show a thigh in public.

I don't really care if people see me naked. Again, this hardly ever happens, but it doesn't trouble me when it does.