I don't know the first thing about making a WA skin, but I did spend over 25 years writing software. So I do know how to poke around and hack stuff. It does look complicated, but maybe I'll take a few months and try to learn the basics of WA skin coding.
Anyway, I was right. It is simple to remove the album art from the main player. Telling me I could rename the .wal to .zip was the key information and made it very easy. There is no need to rename the skin archive file. I used an archiving app called "7-Zip". It lets you look at and edit files within an archive without having to unzip the whole archive. It expands a selected text file to a text editor (or a selected image to an image editor) and if you make any changes it re-compresses the file and puts it back in the archive, replacing the original file. You can also expand a compiled program file within the archive to a hex editor for making changes, but that is 'very, very deep water' and I'm glad I did not have to do that!
After a little poking around, I saw that the file I needed to change was "groups.xml". It contains the " <groupdef id="cpro.normal.overlay"> " which controls what elements the main player contains. Removing the line " <albumart x="112" y="24" w="57" h="57" relatx="0" stretched="1" notfoundImage="cover.notfound" sysregion="1"/> " from this group definition removes the album art image from the main player, without affecting the other windows where album art is displayed.
While there is no hole where the image was, I was also right that the result looks a little strange. You can quickly do this yourself to see what I mean. I think I need to replace the album art image with a graphic or figure out how to get the left side panel (that contains the clock, spectrum analyzer, etc) to expand a little to the right. You're the graphic artist, what do you think?
In time, I may even figure out how to get the spectrum analyzer's fire color option to work. Having the spectrum analyzer look like dancing fire would be a nice effect.
The feature you would like, only having the album art in the main player when it is not being shown elsewhere, would require 2 overlay definitions (1 with and 1 without the album art) and the logic needed (a few carefully placed flags) to know when to switch between them. This would take me awhile to figure out, but the guys at cPro should be able to do it with no problem. But, I have no idea what it would take to get one of them to do this.