what is the most effective way for a ruler to maintain order?

The 'most effective' way for a ruler to maintain order involves running the country in a satisfactory way. This is obviously a very hard, complicated task, but it pays off when you retire and look back to see that no one has revolted against you. The biggest part of this is insuring that the economy is thriving and solid, supporting all people. You have to be sure that everyone is getting what they are due, because it is possible to have a good economy and some people who are getting the short end of the stick. If everyone is happy and busy (ie. employed) they won't want a change, or won't have time to think about it. There are many, many factors involved in maintaining a healthy economy, so it is critical to not be too proud and get the support you need to govern.
You also must give back to the community, showing you understand what everyone needs. It is important to let everyone have their voice, but give them little to complain about (Or just systematically oppress them. This may actually be the most effective way to maintain order, but I personally feel that it is wrong.) This involves reasonably giving the people what they want.

Mr. Stern, I'm sorry if this is a little goofy. I just really like my ideas.

do you agree with jared diamond's thesis?

I agree with Jared Diamond's thesis, which tries to explain all the inequalities in history up to modern globalization. It makes sense that the 'roots of inequality' are things we can't control-'geographic luck'- and that everything else is the result of that until the world begins to share. We can say that Iraq got invaded because of the oil in the ground, but we can invade because we Europeans had horses and pigs and wheat, and an environment that allowed us to cultivate these things and grow communities. The ability to feed support people because of this 'geograhic luck'-different crops, useful animals, and stable environment- meant that we could advance in ways that would allow us to conquer the world.

do the advantages of agriculture and farming outweigh the disadvantages?

I believe the ideal form of human life-style is that of the hunter-gatherer, but I also believe that humans would inevitably give in to the security of farming, possibly assisted by being smarter than the other animals. The main reason I support the hunter-gatherer lifestyle is because I beleive that is our place, where we make the most sense. As hunter-gatherers, part of the ecosystem, like animals. They had a small population, they were predators, and they didn't screw with the grand scheme of things, as any more complex form of human life does. Also, I firmly believe that farming leads to a major shift in what we eat, so that we consume much more dairy and carbs. Alas, humans always want security, and then just a little tiny bit of extra. This is was leads them, very reasonably, to consume a bunch whenever possible in a hunting-gathering situation. This, I believe, is the most inportant reason for farming- the need to accumulation of not neccesary stuff. This allows for population growth, and now you have not only changed the landscape, but added way more people. Et cetera, andthen you have global warming and lots of bad stuff.