Which of the following would you consider to be theft?

[Starry Eyed Jagaloon]

That assumes selfish self-interest to be man’s primary motivator, rather than altruism and cooperation. People would build homes, work fields, labor in factories, perform customer service, prepare food, etc... to provide for others in their community because, in return, others will provide for them. There would be increased difficulty in terms of movement, which has to be worked out, when you won’t have an abundance of available, unoccupied housing units. However, you’d resolve the issue of homelessness when income is no longer the gatekeeper of housing.

So they act out of self interest?

Money is literally just a very liquid representation of what you've done for others which you can in turn use to give others when they do things for you. It's the only way we can line up this mutual, self-interested altruism in a community of any size. The key is to build a system where everyone acting in self interest allows the greatest common good to flourish and we call that system the market economy.

[Starry Eyed Jagaloon]

Georgism is a great political philosophy, but would be impossible to implement as government cannot reasonably be expected to function on a single source of tax revenue.

Well, it really came up before we understood the concept of economic incentives. Sales tax serves to disincentivize spending; sin tax (explicitly) serves to discourage alcohol and tobacco; income tax doesn’t really discourage income, because people like making money.

It’s obvious now that a land tax, like most property/transactional taxes, just serves to discourage people from owning land.

Not quite. Taxes serve to diminish the supply of most goods which is why they hit economic growth. The supply of land is fixed so a land tax won't affect land production. Similarly, demand to own land is extremely inelastic because somebody has to own it for any economic activity to happen ever. This doesn't really apply to most consumer goods and services which is why incentivization works--there's always an alternative product to spend your money on. There is no alternative to land.