Okay so I interpret m. 0-13 to be the tonal introduction, while everything else is purposefully atonal:
m. 0-36: Cellos are not written in alto clef; bass clef or tenor clef is definitely preferred.
m. 1: The triple stop in the cello is ridiculous. I don't know if you intended for all three notes to be played at once, but that's not possible. You're going to want to put a roll marking in there so they know to separate the root from the rest of the chord.
m. 2: Juxtaposing a G7 against a Cm triad is a little weird.
m. 5: A harmonic G on that note is a little bit difficult. You're also going to need to notate if it's an octave up or not. If it is, they need to jump from a normal position to an obscure one just to play that note. If it's not, they'll need to shift to at least 4th position to play it.
m. 7: Cello has Cm, soprano has G7, and piano has D˚... it clashes too much in my opinion.
m. 8-9, 12: Gm and G triads clash too much.
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m. 15: F and A-flat double stop requires thumb position, which doesn't sound very good in pizzicato that high. Also, an awkward shift to get up there.
m. 16: Again, you need a roll or something in the cello. This chord requires a random jump to 6th or 7th position, so maybe take the root out from the bottom and highlight it in the other voices.
m. 26, 32: Pretty high note for a soprano...
m. 33-34: Octaves in the cello are hard and not very useful. The Cm chord needs to be split again.
m. 37-38: Some pianist find grace notes to the same chord to be annoying, but not all do.
m. 38: Cello: having the grace notes with the rolled chord is impossible; you'll need to decide which tones you actually need.
m. 45: Having the harmonic on the B-flat is going to be hard to hit, keeping it straight would be much simpler, since they would already be in position.
m. 49-50: The rhythm writing for the cello is off. Keep things in terms of 4/4, people are going to get confused.
m. 54-55, 56: You can probably have one of how ever many double stops in that measure. Both is going to sound bad.
m. 58: You're looking for tenor clef, not alto clef.
m. 60: Same advice about the rolls or split chords for the cello.
m. 67-68: Are you not going to beam the soprano 16th to the dotted? I only ask because you do it in the other voices.
m. 67-69: Dot slurring 4 notes will make some cellists uncomfortable; two might be easier.
m. 70: Cello: Same advice.
m. 73: I would pick two notes to play in the cello instead of 4.
m. 75, 78, 79-80, 82, 85, 87, 89: Same advice about triple stops for cello.
m. 101-106: Those notes are so short, you'd be fine just having one slash through them... they won't be able to play tremolo.
m. 106-107: Combine all the eighth notes into a couple half notes with the same notation.
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Generally:
Beaming is done to keep the beats in line with each other... like in 4/4 the beaming of the notes is generally going to want to make it look like it's in 4/4, not as if it's 8/8 where the rhythm is variable. If it IS as variable as it is in your piece currently, I'd suggest 8/8, 6/8, etc. in some of your sections.
Cello triple stops are generally bad unless they can be easily rolled; quadruple stops are only okay if there are open strings involved. To counteract the triple stop thing, you can go into the second layer and put the bottom note as a "shorter" note than the top two notes, so it becomes a double stop, or put a roll marking in there. Triple stop triads are generally very hard to play and a string player will assume you're not very used to writing music for them. Also, cellos use tenor clef, not alto clef, which is alto clef shifted up one line.
Your chords in your atonal section (or how I heard it) generally resolve themselves pretty well, so there's just technical things to tend to now. Good luck!