Cool! That feature would be great and would go a long way to helping us. 
The task list you wrote above contained most the features I think we need. To repeat the key ones from there that would make this plugin work as eventbrite killer:
- Guest rsvp
- Event reminders
- Event rsvp list export
- Rsvp custom fields
Other items from your list that are interesting for this purpose:
- Adding multiple events to one topic.
- Recurring events
There are more items on that list where I am not sure of the status and would be glad of an update.
I’d be happy to review this topic for feature suggestions and update the OP with a proposed task list if you like, as I did for the ticket plugin. Let me know.