Hello,
I have gone through the requirements and they sound comprehensive and reasonable to me. Have you got any reactions yet from the osTicket forums. If you post the link to the thread I'll sign up and also follow the conversation there.
This code shall create a descriptive subject field for the osTicket ticket based on the Mibew chat.
Could this be the first message that they user sends (or may be first message of a minimum length, to eliminate messages like "Hello")?
In general I'm fine with everything that has been spelled out. Looking forward to progress on this.