So, here are some pointers regarding the score.
The most consistent error I found was that the string parts don't indicate whether chords of notes should be played divisi or non-divisi. Since the stringed instruments are capable of polyphony (i.e., striking up to 4 notes at once), it is important to notate whether you wish for the chord to be spread out among the players or played as a stop, like so:
(These are the staves for Violin I and II, respectively.) Notice how "div." is written as technique text when the notes split, which indicates that half of the players should play the top note, and the other half plays the bottom. When they come back together, it's helpful to write "unis." above the notes.
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I think you misspelled the clarinet part. In Dutch, the spelling is "Klarinet" (you have "Klatinet").
Bar 2, Bass: going from a slurred bow to a pizz note is impractical unless you want the player to do a left-hand pizz. In that case, a "+" should be placed above the note
Bar 2 and beyond, bass & celli: the half-note pizz will be a bit troubling for players, who are used to seeing pizz notes as quarter notes (or less). When they see the half notes, they may be wondering if you meant to indicate arco (as I did). If you're wanting the pizz effect to be sustained over a half-note beat, I would change those notes to quarter notes and put the expression text "l.v. sempre" beneath the first passage. Or just leave them as quarter notes and be done with it.
Bar 10, woodwinds: it's a good idea to put a dynamic marking in between those hairpins so the players know how loud they're supposed to play
Bar 11 & 12, Fagot: the first G and E... are those to be played "a2" or by only one of the parts?
Bar 14, strings: do you want that slide played as a glissando (a very deliberate slide) or portamento (a more subtle slide)? It sounds more like portamento in the playback. While strings can perform glissando, it's more common (and faster) to perform portamento, which seems more appropriate between the two 8th notes in your piece.
All strings: there are a few passages where you have a pizz note immediately followed by an arco. In practice, it takes a few seconds for a string player to adequately adjust between the two articulations. I would try to avoid that as much as possible and leave at least a quarter note rest in between the switches.
Okay, that's probably enough for now (sorry it's so much!). Please let me know what questions you may have as you look over these tips. You've done a great job; I hope you don't get discouraged reading these!