Nothing has ever indicated to me that the Jedi have had a singular leader until Luke Skywalker, and even then, only out of necessity.
The Jedi always seem to stick to councils, to prevent any one man from having too much power. I will say that at least there are media that explores the possibility of a Jedi trying to gain control of the governments, even in the name of greater good - they invariably end up becoming Dark Jedi because, because even if it's benign reasons, a lust for power is still a lust for power.
Also, there are plenty of media that explore the morality of the Mind Trick - the Jedi are generally not supposed to use it unless absolutely necessary, and even then, they're absolutely required to consider every moral ramification of their actions - after all, Imperial soldiers, guards, and so forth have families, have lives, and have responsibilities - and a Jedi could accidentally ruin any of those without putting much thought into his Mind Trick.
Though one has to wonder - if a Jedi Mind Trick ends up objectively improving someone's lot in life ("You don't want to sell me death sticks. You want to go home and think about your life.") then is it less morally questionable?