1: It was part of the Greek confederation of city states. My point is that having a vast collection of small governments almost ensures that some will be fairly repressive. As for repression in republics, remember that the Tyrant of Syracuse was elected. And that Jefferson lived in a republic which endorsed slavery. In a collection of city states, getting a sufficient weight together to ban something that is considered immoral is very difficult.

2: But the cost of that is falling... Also, a Land Value Tax (as opposed to a Property Tax) counts the unimproved value of the land... (Quite how this even can exist, I have no idea).