There is always the possibility of people being framed for any crime by others who wish them harm, this doesn't mean there shouldn't be a law against it. Currently if you send anyone anything illegal, it's you who will be on the hook for it, not them. Sending them is considered distribution, so the person they're trying to frame should be grateful for those laws.

As far as banning violent video games etc, I'm not sure the depiction of violence and the depiction of sex have similar effects. For one thing, violence is usually depicted as either having a reason of some sort, or being applied indiscriminately towards people of any race or sex. Sexual activity is by nature discriminatory, one gender, or age group, is being "targeted" and therefore "othered" by the person who's consuming the media. This can have a detrimental effect on how that group of people, and their rights, are viewed by the consumer as the media will only take their POV into consideration. The target group is only depicted in the context of what is pleasurable for the consumer. And, because of the nature of the male and female sex drives, even people who aren't searching specifically for the content directed at them will not come across any recordings of this nature in which they are the othered group as opposed to the consumer. This will work to essentially cut them off from ever being able to really empathize with the target of their sexual desires. Instead their biased views of the target group will be confirmed. So the analogy doesn't work - sexual activity is "directed" while violence can be applied to anyone by anyone.

As for minors being charged for owning the nude images of themselves, yes, it's overkill, but that doesn't mean sexual behavior needs to be encouraged when it comes to this demographic. Sexual behavior has consequences, reminding teenagers of that is not a bad thing. That doesn't mean abstinence needs to be preached, but this whole modern day culture of not "kink shaming" and teenagers being put on hormone pills is not the way to go either.