What do city-state personalities mean?

Solution 1:

It affects the kinds of requests the city-state makes. From the game's documentation:

A befriended Friendly City-State will usually make requests that require some peaceful action, like building a Wonder or constructing a Road to them.

Neutral City-States are fairly even-keel, and try to mind their own business.

Influence with a Hostile City-State drops more quickly than normal. They will also make requests to capture neighboring City-States more often.

Compared with other City-States, an Irrational City-State is more random with the requests it makes.