Thank both of you for you comments.
Jamie, Mvt. II definitely would normally have maracas, but well, heh, I hate the midi sound for them, so I settled for the shakers. I would have added tambourine, but I think you should open the midi in an editor and look at it... I had to do all of it by hand, and it was rather tedious.
Mvt. III is the one that I really did have the most trouble with, mainly because that I'm not used to writing slow music. I'm not going to make excuses for myself though, because I do know that I could have done better.
Mvt. IV's ending, to me, reminds me of "ye olden times" of medievel Europe, and that's why I chose it. I love strong chords like it that retain a lot of the french horn sound (I'm not really sure if the midi is portraying it right, but I love french horn, being an ex-player and all). Dynamics are a pain for me, due to the fact that I have to go through and edit each note, due to the program that I use, so all in all, most things are actually the same volume, I've just gotten the instrumentation to sound as though some parts are softer than others. The trumpets actually have 21 measures of rest starting at 1:49. I just relistened to the midi, and frankly, the alto sax voice sounds a lot like the trumpet one, so it's possible that you are mistaken in saying that it's always trumpet, but your sense of too much is most likely different than mine, or anyone else's.
Like I said first thing though, thank you for the comments; I've actually been thinking about giving the third movement a melody, but I can never seem to like what I come up with.