Just noticed there were a few questions in the old thread after it bump-locked, I'll answer them here:
>I don't necessarily want to rely on mercenaries for my defense. If others want to then fine. I just prefer to have my own guns to defend myself.
That's fine, best thing about the market is you get to choose what products you buy. There would undoubtedly be communities that would be defended entirely by volunteer militias in ancapistan, rather than PMCs. Your security insurance company would give you a discount if you owned a gun at home, because you are now a less costly client to insure. If you could certify that you know how to use said gun, and train regularly with it, you'd likely get a further discount. If you and a few dozen other armed individuals trained as a team regularly, and sent proof of this to McInsurance as having formed a local militia, all of you might get an additional discount. Or, McInsurance might decide that a volunteer militia is security enough for your locale, and pay you to provide security instead. I suppose this is technically still mercenary work, but I would guess you were imagining something like anonymous guys in black operator gear patrolling your neighborhood, not well-trained locals.
>How would property rights work for rivers and lakes? Say if a river goes through your property do you own that part of the river or the whole thing?
You would only own that part of the river that goes through your property. So if you were to pollute your portion of the river somehow, and the pollutant was carried downstream into your neighbors property, you would be liable for damages.
>If the rest of the world balkanized would it still be possible to develop advanced technology?
Sure, just look at Europe throughout history. Easily the most technologically advanced continent in the world from the High Middle Ages onward, despite very severe balkanization. If anything, balkanization would promote even faster technological growth due to specialization and the division of labor. Smaller regions would specialize in whatever they have comparative advantage in, and trade with other regions for the rest of their goods. Specializing like this is cheaper and leads to more technological growth, and competition with other regions encourages everyone to maintain peak efficiency rather than slacking off and coasting on established success.
>Could developing space travel still be possible in a world that has been balkanized and consists of tiny countries since space travel was normally state sponsored?
Here's the thing about space, and technology in general. In the market, technological gain at all costs isn't intrinsically good, because it's all about opportunity cost: if the things you give up for technological growth are too severe, it doesn't make sense to pursue technological growth. To use an extreme example, if there's a massive drought happening, it doesn't make sense to mandate that we put all our efforts towards making faster gizmos when more developed irrigation and fertilizer is clearly what the market demands. The same thing applies to space. Thanks to state sponsorship of the space program, we probably ended up going to space earlier than we would have. But that came at the detriment of the rest of the economy; if those taxes that went towards NASA's R&D were allowed to remain in the market, they could have been invested in more conventional tech, like consumer electronics or networking. Spaceflight might have been delayed by ~10 years or so, until telecom satellite technology became viable, but we might have gotten the Internet a decade earlier this is obvioulsy oversimplified, but I hope you take my meaning. And if you look at history, almost every major scientific advancement has come from private individuals fucking around with shit; despite the memes, the state has done comparatively little for tech advancement, and wasn't involved at all until the 20th century. And even then, how much of that could you say was true advancement? NASA's pyramid-building of rockets, while undoubtedly impressive, didn't do very much to establish new scientific principles. It was just a showcase of some very big, and very expensive, feats of engineering. People like to bring up how the Internet was "created" by DARPA as well, but if you look deeper into it, this doesn't really add up. What DARPA created had no resemblance to the Internet as it was used in the private sector, and didn't have the same kind of usability at all. The DARPAnet just sent packets of information unidirectionally from peer to peer. That's nothing what the Internet is like today, and those changes that the private sector made to the Internet was what made it viable.