Improve usability, especially the UI, based on use cases

**Original reporter**: _MikolajKonarski_

This ticket is not about UI improved using the universal principles of visual communication, but about improvements based on down-to-earth analysis or imagining of use cases, user stories, (imagined) experiences with alternative UI mock-ups. etc. In other words, this is the broader question, with research, modelling => personas + scenarios => framework => detailed design.