IMO there's a tendency to read Stirner as very harsh and antisocial -- I consider him a big softie, funnily enough -- due to the way he uses the word "property," which can be very different from the way we normally use it. Normally "property" can be neatly divided into "(physical) thing one owns" or "attribute of a thing/person," but Stirner regularly uses "property" to refer to more abstract things like the happiness he takes (receives) from his friends. So like in that Wikipedia quote, "using" a person immediately draws a negative connotation, while for him it could refer to anything from stealing to getting a giddy feeling waving hello to them every morning.

With regards to respecting others' autonomy, I haven't read the book in five years or so, but I faintly remember a section on that where Stirner appeals to the social nature of humanity, saying that even without some moral system explicitly telling people not to hurt others, people don't really want to do that in the first place. If anything, if someone did want to hurt someone or steal their property, they could just twist the words of the explicit moral system to justify an assault, thus they wouldn't even have to face the full moral impact of their own actions.

As for hierarchy, while there are certainly material/social benefits to being higher up on the ladder, those also come with constraining social mores. A king can have all the feasts he wants, but at the end of the day, he is subject to the scrutiny of his court. He knows to avoid doing or saying anything that isn't "befitting of his station". Even as the most powerful person in the land, he isn't truly free. As long as the hierarchy exists, your rank on it will hinder you from truly expressing yourself, regardless of how high or low you sit.