Hi @Henry Ng Tsz Kiu,
Firstable, thanks for granting me so much of your time as it appears you did a quite attentive analysis of my work.
About tritones, might be, I've got no academic training in writing, so sometimes I do some little mistakes 🙂
This movement may also lack structure, but it's the way it was born progressively in some quite agitated nights.
The clashes between G and F# are intentional ; I regret you not appreciating them maybe the way I do.
Orchestration is not perfect, I agree, especially for the clarinet solo, which questioned me about "adequate support" from the orchestra, as you say.
Thanks for the arco marking missing 😉
Don't worry, there's no discouragement upcoming, those are just the little pains of growing towards better music 🙂
Have a nice day