As to the other part of your question, I will carry the illustration a little further, and in doing so, will answer you in part.
How would you like to have some Michael O'Connor come to you and say, 'Mr.North, I propose to hire you and pay you wages as my body-servant, or my ostler.' Why should you not consent?
If you do not, why should you hire Mike himself to serve you in either of those capacities?
What has become of the golden rule, if you hire a man to do work for you which you would not be hired to do?
"You are feasting with a company of friends; and your domestics, below, hear your cheerful talk, and feel the wide difference between your state and theirs.

Why do you not go down and say, 'Dear fellow-creatures, go up and take our places at table, and let us be servants'?
Does the golden rule require that?
Inequalities in human conditions are a wise and benevolent provision for human happiness, so long as men are dependent on one another, as they are and ever must be.

Some are so constituted by an all-wise God that they are happier to be in subordinate situations.

Mind is lord; and they, seeing and feeling the superiority of others, gladly attach themselves to them as helpers, to be thought for and protected, and to enjoy their approbation.

There is nothing cruel in this, unless it be cruel not to have made all men equal.