Ancaps are usually people who understand economics way better than most people

"The market will fix everything ever! The dirty government just gets in the way!" != a solid understanding of economics. The problem with ancaps is they're all sociopaths or edgy teenagers with no concept of the fact that they wouldn't be the ones running the show, they'd be the workers being exploited.

I can tell you, as an economist, how the fuck are you going to make a system work without private property?

Just because you took AP Micro and Macro doesn't make you an economist friend. As for a system that works without private property and what's wrong with the current capitalist view of it is thoroughly explained in Das Kapital. If you want to be truly informed on economics, shouldn't you read both sides to the argument rather than the anti-socialist rhetoric spoonfed to you through your AP textbooks (developed by a private company, using private manufacturing property, etc.)? Everybody's biased, either a little or a lot, but your teachers and your textbooks certainly have an agenda that they're working to promote (we all do, and this has to be accounted for in our studies) based on the ownership of private property.

You can't repeal the laws of microeconomics

There's so much wrong with this statement that I'm not even sure where to begin. First off, economics as a whole has been widely criticized due to the fact that it is inherently biased, and reliable data can be hard to come by, quantized and record. Economics as it stands makes far too many assumptions to be considered the end all be all of any discussion. Aside from that, it's also important to note how much of economics is meant to be applied to or can only really be applied to capitalist economic systems.

Any system that advocates for the end of private property is both utopian and as unscientific as Scientology

Utopian? Perhaps, but so is imagining just about any economic system as the best it could be. I'd rather take my chances with a government run by the people and goods produced by the people who all collectively control the means of production rather than a private company solely focused on turning as large of a profit as possible. And that's not even getting into the class disparity we see with capitalism....

As for the unscientific bit, the same could be said about capitalism.