I think you have some awesome ideas in this. There are some problems with in terms of orchestration. There are some impossible notes like flute and oboes are incapable of playing A below middle C.
Also the ranges for the instruments. You want to be aware what ranges are most affective in conveying the idea that you want on the instruments. A low flute passage can be sluggish if you meant for it to be fast, and it will probably be drowned out by the orchestra as it's very soft. Low oboe would be loud, thick, heavy and have this honk like sound.
Another thing is that French Horns can't actually glissando, if you have them do it it's usually going up. And if its' going down it's usually faked only really done because the rest of the orchestra is doing it. You could keep it as is but know it might not sound how you imagined it.
You should look into getting a book on orchestration. It'll be your best friend when you write stuff like this. Good work.