This is brilliant, and a much more flexible and high value use of the existing fields - it is also consistent with how most email calendars handle their events.
Would now be a good time to remove the Minimal Event option?
Is there any interest in extending “Location” to include pre-defined/centrally managed locations and, ultimately, room management? E.g. a “room” can only have 1 event occurring in it within a given period of time, so sort of room “reservation”, etc? This would be a huge feature for enabling conferences, but also potentially managing events for real-world communities with associated spaces.
Location list would be great indeed. Maybe for the moment you may use the calendar feature and make a parent category for the location, then a sub category for each room. All the reservations would be topic created with an event in it and will appear on the category calendar of this category(room). One drawback is the event system does not take concurrent event into account however if you are in a community with a bit of receptivity you may ask to check if there is already a reservation at this time before and after the reservation is created.