I haven't read the whole piece and probably will not get to it tonight, but there are problems with your argument right away. I skipped all the stuff about Rothbard, because it literally does not matter what Rothbard said or what Kinsella or Wenzel thinks he said -- the task is to justify the noxious concept of "IP."
1) Kinsella argues that distinction between which IP is protectable and which IP is not protectable is arbitrary. For example, why are novels protected by copyright, but not fashion designs or recipes? Since we can’t make a rigorous distinction between what is protectable and what is not, there is something wrong with the concept of IP.
It is indeed arbitrary, and there are plenty of other examples besides just fashion designs or recipes. But let's look at your answer to this.
Well, you can certainly copyright a book of recipes, or a book of fashion designs. So I would say that fashion designs and recipes can be copyrighted.
If you write a book, you automatically have a copyright in it, thanks to the current copyright statute. What's in it for this purpose is immaterial. The "copyrighted" thing in your example is a book.
Why is it that it seems reasonable to copyright a book of recipes, but not reasonable to copyright a single recipe?
It does not seem reasonable to me.
It appears to be a question of length and relates more to what the private law, as evolved through the market process, would set as a reasonable standard.
But copyright is a statutory creation, not something that evolved from a market process.
For example, how much smoke pollution would you have to endure from your neighbor before you could sue him? The answer is somewhere between one molecule of smoke and total inundation of your property, and the legal system would sort that out through the market process. The same process would apply to IP.
I am not a law-talking dude but your example sounds like it would be classified under trespass, which has zero to do with either copyright or the larger notion of "IP."
That's all I got now, but if your other points are this shaky, I wouldn't expect your argument to hold together very well.