Maybe a tag cloud or list for locations.
Maybe some way to sort by continent -> country -> state/province -> city/town.
Separate past from future events. Currently on going events listed on top or otherwise prominent.
Be competitive with whatever https://joinmobilizon.org/en/ is going to be. lol.
Maybe allow Group Admins to create events as the group (instead of as an individual) and have a separate list and/or sticky status for an event.