[DanCooper]

To be precise I can get ember to scrape the season names but Kodi's scraping won't "see" them from the nfo.

Because there is no "official" place to save that information (same for season plot). If you want to get that inforamtion to Kodi you've to use the Kodi Interface (Settings => Modules) in Ember to sync.
 

Also is there any option I'm forgetting that will enable ember to overwrite image files? (SMB share, permissions are fine) I have to delete existing files if I want to change artwork.

If you've added the source as UNC path (\\SERVERNAME\SHARE) you've to set the username and passwort in Windows. Another user had the same problem but i can't remember the solution and i also don't know the thread or post.