I think nudity should be allowed, as well as "free speech zones" on Steemit.
Just like with Reddit, a person should be asked if they are 18+, and if they click yes then it should take them to the unrestricted part of the site. In addition, if people decide then there should be parts of the site with free speech where any sort of opinion can be expressed pseudo-anonymously, but with warnings for people not to give out their personal information.
In my opinion, free speech is more important to a free society than the ability to censor. At the same time for legal reasons, people have to be given the age disclaimer, and be warned up front that a certain part of Steemit is the free speech part.
In the United States the law is pretty clear in favor of free speech. At the same time there is a social need for pseudo anonymous speech which you sometimes see on Reddit or on 4chan so that people can discuss topics which are sensitive but necessary to be discussed.
Unfortunately, the actual law on free speech is far from clear in the US. Lawyers have, over time, massively corrupted the concept of free speech in the US, to the point that actual laws regarding free speech are understood by only a few. If you take a bar exam, you'll find that free speech questions are some of the most tricky to answer because of all the case law you have to know in order to see how this simple concept has been twisted around. This actually goes for most "constitutional law" in general, but the abuse of the concept of free speech is particularly egregious (probably because it's the most "dangerous" to established viewpoints).
I think there should be "non-free speech zones". Everywhere else on the site free speech should be welcome by default.