How we cite our quotes: Stephanus pagination (the standardized way in which every text of Plato is divided). Every edition and translation will have this pagination in the margins.
Quote #4
"Then the man who's going to be a fine and good guardian of the city for us will in his nature be philosophic, spirited, swift, and strong." (376c)
Socrates's recipe for a ruler emphasizes the importance not only of philosophy but also of courage ("spiritedness") and strength. Socrates insists that a ruler must be a well-rounded individual. He doesn't allow any shortcuts.
Quote #5
"....no one will posses any private property, except for what's entirely necessary." (416d)
Many people have seen Plato's Republic as a surprising precursor to more modern ideas such as communism and socialism. Many people are suspicious of "utopian" ideas like Plato's because they see them as inevitably totalitarian. What's the difference between a utopian society like the one in Plato's Republic and the dystopian societies in, say, Brave New World or 1984?
Quote #6
"...in founding the city we are not looking to the exceptional happiness of any one group among us but, as far as possible, that of the city as a whole." (420c)
For a guy who doesn't have a lot of confidence in "the many," Socrates has a very pragmatic take on what the priorities of this city should be: the happiness of the city as a whole (and not just of one particular group of people).