Here i will answer your question, Equestrian is a monarchy. Their is no king or Queen so that the people have more power as having a queen would give them more power, still its full of Providences. manehatten is one of the, the mayer is basically just an elected Duke for the city while places like ponyvill have a real mayer, each princess rules a chunk of the kingdom, while celestia has the most control, thy are not the only authority figurs, their are many nobles in canterlot, blue blood is not one of them as he is a prince but their are a few known ones, you see the elite or at least a chunck of them are noble, fancy pants can be assumed to be one of them as he is seen as the most important pony in canterlot, he is able to autherise construction in the city and and pipe work so he would have to have some kind of power, after that his friends are nobles or can be assumed as nobles and most of the ponys, now what i take in the show is thy never show us the population but i assume that its at a 1:10 ratio because their is only so much that can be fit into each episode and a population of 60 ponys in ponyvill is not realistic. other than that the kingdom lets most of equestrian govern them self while still being able to collect a tax and impose rules and laws.