Hi Mirko,
1.) Yes you can (You have three different spots to show them, on the event-list / upcoming view or 2 on the detail page) and you can set them per category
2.) No, currently not - have that on my todo-list
3.)Yes to all, except price range (only free and paid)
4.) Yes it can, organizers can only manage their own events in the frontend per default (bookings, texts, emails, contacts etc.) and are normal Joomla users.
5.) The event description supports plugins, so you can just use something like siggallery for that. So yes that's possible with additional (free) extensions.
6.) We currently have alpha point support, which is maybe what you are looking for. But we don't have an own subscription implementation.
Kind regards,
Yves