Comprehension:

What are you told of Dorian Gray's lifestyle?
Dorian Gray is very proud to open his beautiful house and "to charm" his guests. His way of dressing and style had their marked influence on young people of refined tastes.
What is for him the greatest of arts?
He considers life as the greatest of arts, and for all the others arts seems to be just a preparation.
Why is Dorian Gray an ideal for educated young men? Why is being consulted on matters of fashion not enough for Dorian?
He seems to be an ideal for educated young men because he represents the modernity of beauty, so he becomes somebody to copy in order to fashioned other people. For Dorian it is not enough because he doesn't want to be just an "arbiter elegantarium", he seeks to elaborate some new scheme of life that would have its reasoned philosophy and its ordered principles, and find in the spiritualising of the senses its highest realization.
What are the principles of Dorian's "new Hedonism"?
Dorian's "new Hedonism" is based on the re-creation of life and to save it from Puritanism.

Interpretation:

What kind of narrator does Wild use in his novel? Do you feel his presence?
The point of view is third person, omniscient.
What idea of life is expressed in the final sentence of the passage?
In the final sentence the idea of life expressed is to teach man about each single moment of life that is itself a moment. Life is produced by every single moment of living.
Walter Pater (1839-1894), the forerunner of the aesthetic movement, expressed the same concept of life in is collection of essays. Studies in the History of Renaissance (1873) which he concluded with the following words: "Not the fruit of experience, but experience itself, is the end. A counted number of pulses only is given to us of a variegated, dramatic life." Where in the last paragraph does Wild quote Pater?
Its aim, indeed, was to be experience itself, and not the fruits of experience, sweet or bitter as they might be.