The comic, and the deeper philosophical meaning talks about a lower bound, not an upper bound (pick your own point of reference).

What is necessary to force a system against somebody else's will. A gift or exchange implies agreement and cooperation.

Unethical is a matter of prospective and degrees.

This pig is obviously a capitalist libertarian private property owner stand-in. If you exploit other people's labor by paying them a wage lower than the value of their labor, you are effectively stealing from them. Profits are theft via extortion.

You may say "they both agree to this, that's what makes it ethical". I disagree. If you are held at gunpoint, you will do what the person says, it doesn't mean it was willing. This is called being "under duress". If not working for a property owner means that you face homelessness, starvation, and police violence; your life is similarly threatened.

the owner abused the poor people, because he has a capital and they don't. and he will now charge them everything they have for the rest of their lives.

in wild west, people used guns to take everything from you, we live in a world where people with money convinced people without them to forgo weapons and accept money as a means to play the same game, and he used his money against them in the exact same manner as he would use the weapons. and so you can argue it is unethical in a same way as being robbed at gunpoint.

and this their power is only power because we tolerate it. this comics is about what happens when we finally stop.

Eminent domain. As implemented in the US, the government needs to pay for something if it takes it using eminent domain, so it's not really a mechanism to move wealth around.

You'd normally use it when the value to the public of something is much higher than to the individual. Like, say someone has a piece of property that they don't want to sell, but it's blocking an interstate highway that a ton of people need to use. The value of the one piece of property is limited, but blocking the construction of the highway is a big deal; it lets the government say "you don't get to choose not to sell". The government still pays for the property.

This is ridiculously wrong.

Most violence (and crime in general) between humans tends to happen due to harsh living conditions. If you're struggling to make ends meet, you take what you can however you need if you're desperate enough.

As technology has improved (and more importantly, was obtainable by more people), living conditions have also improved. Hence why crime rates go down