The music has a very cinematic feel. Depending on your goals, that's either a compliment or a criticism, because nowadays the same qualities that make a piece good movie background music makes it rather boring to listen to by itself. For a movie, you want music that supports the visuals yet doesn't draw attention to itself. I think what you've composed would do that very well. And that's also why someone might be dissatisfied listening to it unadorned. Listening to modern movie music without any visuals in front of you is sort of like listening to Beethoven's 5th without the horn section.
As far as the jumping around, that also depends on the visuals. What's on the screen at the time will determine whether the final piece has to be chopped up even more or have some ideas drawn out and extended.
I think Ray brought up a good point. It might not be a good idea for the same person to direct and score the same movie, especially if you are really attached to your music; you have to be pretty ruthless about bending the music to the will of the visuals. There was a time, especially during the 40's through the early 60's, when film scores were often composed to stand on their own, but that is no longer the case. I suppose from a film-maker's perspective, that's a good thing, but as a composer, I regret the end of that era.
It's just a group of friends and I working on an indie film together (all teenagers), and I'm the only one who can compose, and the only one who has a camera and I've taken some classes before on filming video. About the low quality sound, I have about zero budget, and although I am saving up for better stuff, I currently can't afford anything the the sounds that come with Finale PrintMusic.
I think - all things taken into account - this is a pretty solid idea for a score. As you mention you are just starting out and are a little limited in what you can achieve. I think there may be scope for creating the score with what you do have that sounds good however. Also a sampling application might mean that you can cut some corners by sampling music from the classical cannon.
It does sound like to me that underneath all this midi guff - there is a pretty good composer trying to escape. :)