How well did Athens live up to the ideals it set for itself?

Not very well. To begin with, the idealization of Athens as the 'birthplace of democracy" is largely a 19th century invention of the poet Lord Byron who was an ardent supporter of Greece's struggle against the Ottoman Empire and who tried to win over the European powers to support Greece's independence efforts.

In reality, Athens - for a relatively short period - had a form of democracy consisting of mass meeting consultation on a limited number of subjects, but the real power remained with the ruling families of Athens who saw to it that all power remained firmly in their hands.

Athens' ideals mostly revolved around dominance, expansion and trade and they never even tried to institute their brand of democracy in other city-States or even in their own colonies. Athens was an Olicharchy and was happy to see power concentrated in the hands of a few powerful families elsewhere as well.