The rest of your post is just opinion. Of course you are entitled to your opinion but so is everyone else and provided you don't do any harm to the rest of society, you are encouraged to act on your opinions.
What "harm to society" means is also just opinion. Every member of that society of yours has a different opinion on that. Some people think that drawing a cartoon of their imaginary friend causes such "harm to society" that it must be punished by death.
Whose opinion is valid? Everybody's? Then surely I am "harming society" whatever I do because some people will have contradictory opinions. Not Everybody's? Well then I'm not entitled to my opinion, am I?
My belief in the NAP might "just" be opinion, but at least it's consistent with everyone being entitled to an opinion, and encouraged to act on it as long as they don't aggress against any individuals. See, no internal contradictions in my opinion.
Your pro-IP stance is also "just" an opinion. But if that is your opinion, you cannot simultaneously hold the opinion that theft of physical property is a crime. Or at least not without contradicting yourself.
People organise together to form societies. The societies make rules to make life better. If one person decides to break these rules because it benefits him to the detriment of the rest of society, its hardly unreasonable to say that person will be punished.
In the case of intellectual property, if one person is investing $100 million to make a drug, and someone else takes the finished product and copies it and sells it for less than the inventor, the inventor loses his $100 million and no more drugs will be developed. If we, as a society, want to encourage drug development, that's a bad result. No matter what moral basis you operate on, you cannot be allowed to harm the rest of society simply because you are greedy enough to want to profit from selling medicine but too lazy to do the research.
How you kid yourself that stealing IP doesn't harm other people baffles me...but then the advocates of slavery also believed they were morally right.