Hi Paolo,
thanks for testing the beta and for reporting your experiences! Some comments and questions from me:
"-week view does not work (no day is shown) if there are no events"
That's by design. The week view time scale shows by default only those times where events start or end. If there are no events in that week, there's no time scale. However, you can enforce the week view to show the complete 24 hour scale by enabling the "Week View Full Time Scale" option in the module settings (section "Week View Settings" in version 4.0.0, "General Settings" in 3.3.8).
"-it is not possible to select a single day"
You mean to get a list of all events of a single day? You can get such a list, if you check the "Disable Month View Cell Events" option ("Month View Settings" in 4.0.0, "General Settings" in 3.3.8), and then click on one of the days with events. This option works best with the "Small" module theme, where the days with events are highlighed, and is meant for a quick event overview in the left or right pane of the homepage or some kind of overview page.
"-list view seems useless"
Could you explain that a bit? Currently the list view is used mainly to have a short list of the next few upcoming events, on the homepage or so. Do you have another use case in mind?