[Montellese]

• I just wish you imported episode thumbnails into kodi named 'thumbnail'.
  

I'll look into this. It should be easy to fix. Unfortunately the whole artwork naming in Kodi is not very straight forward and has changed a few times which makes it hard to figure out what the proper art types are. I've never noticed any issues with Estuary but I've never tested any other skin.

• Have you thought about importing plex playlists into kodi?
  

How would that work? You mean instead of importing whole libraries? Or in addition to the libraries as playlists in Kodi? Kodi doesn't really have a playlist database. I've never used playlists myself (in Kodi or in Plex) so I'm not really familiar with the topic and would need help with something like this.

• When you import rating(s) into kodi is it possible for you to set a default source? I'm guessing that's normally done by a scrapper but since you don't use one it doesn't get set for the movies/shows/episodes. This means that ratings don't display in the skin.
  

The Plex API wrapper I'm using offers a rating and userRating property for each media item. I can see ratings for all imported movies, tvshows etc. but I've never used user ratings so no idea if they are working properly. I'm not sure what default source you want to choose. This should be handled by Plex's scraper and media import should just import it into Kodi.

• One idea that might take a bit of time to do is finding out how plex handles its theme tunes, and incorporating that into kodi. I know plex has its own online collection of 30 second audio clips (any longer breaches copyright laws) for the theme but it also checks local first and plays them instead.
  

TV show themes is not an official Kodi feature. AFAIK it is supported by some add-on / skin combination so it's rather difficult to integrate it into the media importer add-on right now because it only really uses official Kodi features.