[LongMan]

Seems like you have figured most things out. Happy to hear that.

With regards to the Main node, that would be used in the Main Menu in the same way that you have Movies, and TV Shows in Estuary on the left. The other nodes I referenced are for the widgets. The other ones you are asking about are for the sub menus. These are already present as default video nodes for movies and tv shows in userdata/library/videos. My advice, copy those and add your rule.
eg.
    <rule field="path" operator="contains">
        <value>4K</value>
    </rule>

With regards to filter vs folder, as stated above I use filter for stuff scanned into the library and folder for things that are not.

eg.
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<node order="3" type="folder" visible="True">
       <label>Home Videos</label>
       <icon>DefaultAddonVideo.png</icon>
       <path pathversion="1">smb://NAS/Home Videos/</path>
</node>

I see that you have figured out that unlike movies which have just one value for content, tv shows can have two , namely tv shows or episodes. You will ind a similar thing for music if you venture there. Content can be artists, albums or songs. @DaveBlake have done a lot of work on music library making it real easy and flexible. I think there is still some work left with ordering but, for the most part, it is on par with and in some cases better that video right now


The power of Kodi is that you can make it your Kodi as oppose to being handed what someone thinks is best for you. I for example don't use the in progress node, I use a last viewed. Often times I will watch the first 20-30 minutes of a show and then the show watch me for the hour. The show is complete and marked as watched so no longer in progress but I have seen only 20 minutes of it. By having a last viewed node, the last video that I 'watched' is right there for me to continue.

So keep experimenting until you make your Kodi.

Hope this helps.
Cheers,
LongMan