-Has read Nietzsche-
-Has also read Nietzsche, or at least knows of him-
I think ChairmanPoo has got it. You may want to take a look at the TV Tropes page for Friedrich Nietzsche, it does a fairly good job of explaining his view in tropes. Nietzsche's ideas may have been controversial (and still are today), but you have to be careful not to take his quotes out of context.
-Why French Revolution, when you have diplomacy?-
It
can be difficult to convince the kings to up and leave their fortunes to the poor, or for wealthy landowners to pay their servants a bit more, or even for the then-incumbent King Louie XVI to do a better at job at being a... king. The French people were suffering from extended periods of poor harvest and the results of a defeat in the Seven Years' War (heavily increased taxes due to massive government debt), and it was easy to see the rich, who were living in luxury over the vast majority starving people, as being somewhat tyrannical. When starving, and covered in dirt, it is difficult to even find audience with powerful people, and more difficult still to find the patience for it.
-Modern art is not art-
Debating what is or isn't art is largely useless, because what does or does not constitute art is largely up to one's personal preferences. Wikipedia (the best source of information) says that "Art is a diverse range of human activities in creating visual, auditory or performing artifacts (artworks), expressing the author's imaginative or technical skill, intended to be appreciated for their beauty or emotional power." Maybe making a chair out of junk does not exactly express the author's imaginative or technical skill, but such objects may still be appreciated for some hidden symbolism. I don't necessarily like most of what comes out these days as art, but the label 'Modern Art' is extremely diverse and it pays to have a closer look at it before classifying all modern art as similarly devoid of taste or meaning.
d) In what way it is a self-fulfilling prophecy?
Consider asking yourself why the person would feel this way instead of asking them, and you will learn a valuable lesson in empathy.
Hey, did you know that your "great country" was founded by a bunch of slave owners who said that all man are created equal?
For better or for worse, that was what kick started America, one of the great powers in this day and age. There's no need to kick the dead horse on this one, because all it will do is make people annoyed at you for bringing up issues that are so far in the past that they have ceased to be relevant. If it grates on your nerves that people call their countries great despite having been founded by slaving misogynists, consider that slavery was prevalent in many early societies and that therefore almost all people living in modern times have in some way been affected by slavery in the distant, distant past.
Anyway, that's what I needed to get off my chest.