We've gone over what Hope is and what you can do with it. Now let's talk about the other half of your Pool: Destiny. Destiny is that spark of greatness that every budding hero has. It's that thing about him that makes the camera settle on him. It's what makes him a leading player in this story as opposed to a supporting cast member.
Okay, so what can you do with it. First, every Destiny point you spend it worth 2 effort. That means that by using Destiny you can accomplish much more than by spending Hope. Destiny is the stuff of greatness. Dig deep here, and you'll blow the doors off any normal person.
As an added bonus, Destiny isn't concerned with skill limitations. You can spend Destiny in any amount for any action. Got a sword skill of 3? You can spend 3 Hope on any sword action, maximum. You can spend any amount of Destiny though, and get double the effort for it to boot. Hell, you can spend 8 Destiny on a sword action even if you don't have a sword skill. Let's face it, when's the last time you saw an awesome hero in an epic be faced with something he couldn't do because he lacked the training? Characters with a big Destiny rating aren't limited by things like a poor education, be it academic or physical. They're limited by clever and powerful opposition actively putting roadblocks in their way. When you start tossing Destiny around, trivial matters like "did you take the skill" get thrown out the window.
Destiny isn't tied to any of your hopes. It exists as a free pool that transcends such mortal concerns like a quiet life. I'm very tempted to give destinies some kind of flavor, like Revolution, Revenge, Justice, Sacrifice, Salvation, etc., but for the moment I don't have anything like that. It sounds like a neat idea, and likely one I'll return to sometime. For right now though I'm not sure how it would work. So, for the moment, Destiny isn't tied to anything.