Sorry this was a bit later to reply to (the ATF / Discord emoji issue & irl stuff took longer to do than planned).
Ok,
so #1 - that seems a reasonable thing to try & implement as there's no consistent way to get branding artwork from a stream (was tried with SHOUTcast but it flopped really hard). The image you see is the hard-coded default though on the 'album art' preferences page there is a way to override that image if wanted. I've logged this as something to look into as there's a few things I'll need to sort out with artwork & the artwork plug-in to be able to cleanly support it.
For #2 - I've not provided a simple zip version of what is in winamp_res.dll (which is PNG & setup to help me do some core engine overrides more easily) as I didn't think there was any interest for it. As it's the 5.666 files with some wacupification & fixing some visual quirks with the skin. Editing the dll can work but it needs to be the same resource id & type & also format (png) & like was noted that will get replaced when the build gets updated.
Looking over the posts I see it's just not having any text in the titlebar - is that something wanted on all windows or just the main window? As you can just use the image files needed (extract or from the base skin - I'll have to sort out a correctly named copy as I just store things by resource id instead of the winamp core filename expected) & put them in their own folder in the main 'Skins' folder & then select that as the skin.
Any images you don't need to edit will then just fall back to the built-in ones so depending on your needs it could just be main.bmp/main.png (WACUP supports saving & loading the classic skin images as PNG) or it'll normally need a few more for eq, playlist & generic windows but that's not hard to do
-dro