As you're already aware of it I won't spend an age griping about it, but I agree with you about the harp sound.
The tempo is fine, it probably is that you've heard this a lot of times.
The section that has just the bass and harp does begin to feel too sparse after a while, even with the second harp line added in. Though the entry of the instruments at 2:04 is brilliant, I wish the harp would drop an octave or something, it gets a little too piercing at the higher parts and I'm not convinced it's just the sound.
2:59 is sublime; I wish there was more of a buildup than a timpani roll, though, because the string passage is very emotionally written. But the really high strings could probably use being played an octave lower as well, just to give it even more of a lush thickness.
How everything drops out save the one instrument at 3:54ish is very nice, though having a little more reverb on the instruments being removed would have been nice just to make it seem less abrupt.
After that attempt at critique--I think you've got some very good ideas here; I love your melody and harmony work and your general skills at arranging the instruments. The flute solo does also work very well, if I haven't mentioned that already. I could see this working very well in a ominous setting in an RPG. Two off of ten, simply to try and encourage you to fix that harp sound, which is the one thing that threw me off majorly in this piece. Very nice work, overall.