How do I copy JEvents between two sites?

I'm in the midst of redesigning a site and migrating from Joomla Event Manager to JEvents. We have three version of our site at this moment: a live site (which is still running as is with JEM), a test site, used for testing JEvents, imports, settings etc. and a work-in-progress site which is going to be our new site if all is done.

I've managed to get my settings right on the test site and now I want to copy this to our work-in-progress.

1. I've made a backup of all JEvents tables in sql format. I've copied the records concerning JEvents and the JEvents related records in the ##_categories table, keeping the same id.
   
2. I've done a fresh install of JEvents and the plugins.
   
3. Then I imported the sql backup and overwritten the empty JEvents tables
   

This doesn't seem work to well:

• The events that were copied this way can't be deleted.
  
• The custom fields are gone, that is: they exist with an event (the #_jev_customfields is filled), but I can't see and edit them in the admin, the default custom fields are there, and I don't see any fields when editing an event.
  
• The settings of JEvents and plugins like the locations plugins don't seem te be copied. All settings are back to the default.
  

Clearly I've missed something here and not everything has been copied from one site to the other. What did I leave out? And what is the best way to copy JEvents between two sites?