It's a good idea to speak with youth who have actually participated in protests, or just conduct a survey in general about what issues are most important to youth. Very often there is a disconnect and misunderstanding regarding issues that adults see as most crucial and what the youth see as most critical. Ask youth what do they think about their futures.
One option would be to discuss the history of generational conflict-- when two generations (one youth, one older) compete in society for the resources available. Much of the history of youth unrest can probably be traced back to conflict between an older and younger generation. Finding the commonalities between various youth unrest throughout history might make for an interesting essay.
I would examine the different causes of unrest. In addition to that, you could identify how the unrest affects the individual, or group. I agree that the unrest itself needs to be analyzed, in terms of what the unrest can do (bring change or not). Is the unrest true dissatisfaction with the world, or is it dissatisfaction with the life of the individual?
One cause of youth unrest would be dissatisfaction among young people with the status quo and a desire to change it. Often young people (justifiably, I think) are frustrated with their inability to control their own lives, and the fact that older people, from their parents to politicians, are making decisions for them. They perceive that their futures are out of their control, and that decisions are made without taking their interests into account. In this sense, "youth unrest," often seen as evidence of society's imminent collapse by older people, is really an expression of anxieties about the future. Some historians have interpreted the unrest of the 1960s in these terms, and certainly many observers have made similar arguments about the Occupy protests. So a good essay might compare examples of youth unrest over time and across cultures.
I would think that a good essay would be built around why unrest happens and whether it is a positive force in the world or in a particular country. For me, this would be the most interesting thing to look at -- look at what factors bring unrest about and whether the unrest is going to help improve things.