Good feedback. Due to how the dialogue system is designed and coded redesigning the flow of the branching options might be impossible. Some parts of it can get restructured but it could cause new problems so it's too early to say. The main branching questions in Shelly's dialogue specifically are intended to be hectic and disorienting so I don't think their structure will be changing. That said, making the dialogue experience as smooth as possible is a top priority and I'll look into it.
It would be nice as well, if there was some kind of indicator, to know if a character has something new to say regarding one of the questions that I have already asked.
Main topics already have this. The case piece inquiries generally don't update except in special cases where relevant information is found. Making and verifying the assumption that a Case Piece's dialogue might have updated with a specific person is an intended part of the gameplay but it only happens a single time in the demo.
If you highly enjoyed the demo please consider giving its page a rating.