In terms of composition, I don't think the piano fits very well with the rest of the instruments with the basic arpeggiation that you're having it play over and over. The rest of the instruments sound fine to me, and there don't seem to be much in terms of clashing instruments.
The song does get quite a bit repetitive though, and could certainly use a second part to it.
Now sound-wise.... there's much to be desired. Being a fellow FL Studio user and EWQL user, I would suggest that you play around with EW a bit more to bring out more of the sound from it. Stormdrum is excellent, but for the drums you have in there EWQL Symphonic has all that you need.
You should also look into EQ and compression to help bring out the sound. Being an orchestral piece, compression isn't that necessary but you should use EQ to help it out. Particularly the piano, which could shine a lot more with proper EQ.
Keep it up! :D
~Phyrnna ^_^ <3
P.S. I think you've got potential, so I scouted you. :D