Just a heads up. The browse feature is not working for me. When I select another directory with images, the editor no longer loads the images on Roaming\Strive but it doesnt load the images on the selected directory either. It also doesnt display the new directory next to the browse button as well, but instead keeps displaying Roaming\Strive. Ive tried multiple things such as another hard drive, moving the editor to the same directory, renaming the images and putting them inside the games folder structure(Strive\bodies or portraits\) within the selected directory (which shouldnt be necessary anyway). Yet nothing worked. 

Here is my wish list aside from some things you already mentioned:

Eye color tab next to hair color
A small rectangle/circle next to the eye/hair colors tags displaying its respective color. Alternatively you could add the colors as background to the tags 'box'(the area highlighted by the mouse).
A small "special attributes" tab to add simplified tags such as Horns, Wings, Tail, NonHumanEars, and any others that I may be missing. 
Turn gray all tags added by folder names and make them uncheckable. Alternatively you could make it so that checking sex, race and age tags would move the image to a different proper directory, but this probably wouldnt work well with everyone using their own folder structure.
Instead of a red font for non-standard race colors how about darkish yellow or orange? This is because the red font color often signifies something that must not be used/done to the point that doing so can potentially cause conflicts or crashes. Its not that heavy of an issue here.
Image selection(should work like windows does it for files/folders):
Left mouse click to select 1 image
Shift+Left mouse click to select all images starting from the previously selected one to the last selected one
Ctrl+Left mouse click to add 1 image to current selection
Add a '# images selected' text 

Keyboard Shortcuts (based on the current editor layout):
Enter to apply, pagedown/DOWN for next image, pageup/UP for previous image, RIGHT for fist image from the next race, LEFT for first image from the previous race, Backspace to restore last saved tags, Delete to remove all tags(excluding the ones set by folder names)

Maybe support multi-portrait editing in this manner:

shift+ctrl-click to select multiple. Once multiple are selected, all checkboxes get unchecked (once initially going into multi-mode).  After that, checking boxes, and and clicking apply, it looks at each, and each section that has something selected, it applies that to all the files?

I still want to allow picking non-standard colors for races, as you can modify them via dye's etc., but did think about changing their color to red to signify they're not a standard color for the current race(s).

Agreed on shifting the file selection, the portraits are mostly vertical anyways so there's extra horizontal space. So move that over,  then maybe stick the portrait photo above it or something so you see both body and portrait?

I was also thinking a filter for the file list, can type in text, and it filters the list to only items that match it.

Was one concern, right now this could lead to overwriting of different portraits.Instead of an incrementing number at the end, I'm thinking of a partial hash of the image instead. If it's the same image, it'll be identical, and so if it overwrites it should only overwrite an identically tagged identical image.  

Both of those were fixed in 0.4 or 0.5.

Sigh, i screwed up the regex when putting it in settings.json, line 44, the Male line, should look like this:
{ "Name": "Male", "Regex": "(?<!Fe)Male", "Tag": "Male"},

Will post a 0.6 with this and Bark -> Dark shortly.

{ "Name": "Dark Elf", "Regex": "DarkElf", "Tag": "DarkElf"},

{ "Name": "Elf", "Regex": "(?<!Dark)Elf", "Tag": "DarkElf"}, 

You're free to change the regex and list for the skin colors. I left it as-is to allow someone to choose which tag from the list, even if it's a bit unintuitive currently.

Enter applies now, and escape resets.  Additionally, instead of coloring things in the list, I just added checkbox filters for race, hair, skin, tits, and ass missing.  Check the box, and it filters the list to only the ones missing the selected attributes.

I think this allows for a good workflow, can filter to everything missing tits, have mouse over tits area, select tits, hit enter, hit down, select tits, hit enter, hit down, repeat. Can work through an entire list for one attribute with minimal mouse movement now.

Replying to the wrong post? this is the editor, not the mod.

0.5.19b was broken for mod's I vaguely recall? Use a newer or later version.

Hmm, random portrait should re-roll the portrait. If it does nothing, almost sounds like the game's built-in random portrait functionality is still at work and not the mod. Or something else is going on.  If you edit settings.gd in the mod's folder and change
var debug = false
to
var debug = true

then re-run the game, it should output on the console a bunch of data about portraits it found, and when it tries to randomly assign a portrait, what it's assigning and why.

Gender is a hard rule, and Age is a bit fuzzy, it tries to be a hard rule, but if too few results, it relaxes things a bit.  If it's only doing race as a hard rule, that's what the game's default logic does, so sounds like the mod didn't fully apply.  When you applied this to the game, was it a fresh extraction of the new version?

So the formats are actually all .jpeg (I though there was others but I was mistaken).

I always will find a set of pictures to add, place them in portrait, and then copy all of them and place copies in bodies.

On a separate note: does selected more than one option per category, (like picking multiple tit size check boxes), make that picture be randomly chosen more or less often?

I should add a check for errors on that and avoid moving, and ideally also have it rollback changes if it moves one, but fails on the other (like if for some reason a file already exists with the target name, or it fails to create a folder, etc.)

Hair and Fur are considered one tag, mainly because a given race can only have one of those, none of them have both a skin and a fur color.

I do like the idea though of marking colors that are never normally picked by the game for selected race(s).  Maybe mark it red if none of the selected races can have that color, yellow if some of them can (in case someone is applying multiple for some reason).

I don't see adding a copy option instead of move.  You can achieve this outside the editor easily by only working on a copy of the files, which honestly I'd recommend anyways.

It's written in C# using WPF.  Youcan possibly build it using msbuild from command line, but I'd recommend downloading Visual Studio.  I believe it should work with the Community edition that is free.  https://visualstudio.microsoft.com/downloads/

I haven't used the app, so I don't know exactly what your problem is, but I know the game quite well. I would recommend verifying that the images with the same name, also have the same relative path from the "portraits" and "bodies" folders. For example:

...\portraits\Human\Blond\TitsM\SkinL\AssM\girl(1).png

...\bodies\Human\Blond\TitsM\SkinL\AssM\girl(1).png