The important thing to remember about dealing with a path is that it is a primitive, it isn't a container for other entities like a sheet, symbol or multipoly is. As such, you cannot access the line segments in the path, because it doesn't contain any, it just contains nodes. So there isn't a way to get a reference to these before exploding. You can figure out what the lines will be by looking at the nodes in the path, but there aren't lines to get references to. (Also, changes in the drawing list can cause things to shift around in memory, so holding a pointer to an entity in the drawing list that was acquired prior to a modification may very well not be valid anymore.)

I haven't tried exploding from code myself, but I guess that would be the EExplode function. That function does have a parameter of type EXPPROC which looks like a callback function, maybe that could be of some use in determining the new lines, but I haven't really figured out how to use it properly.

If you make those palette swatches hotspots with appropriate macros, you can switch on a click without having to start the :CC2KEEP: command all the time. A bit more work to set up and change, but easier to use.

You're right that the size of the map doesn't matter, although the aspect ratio does if you want the entire map. If you are happy with the wallpaper being a cutout of the complete map, then it is less important.

What I would have done is making a map with the appropriate aspect ration (For example for a small dungeon map, 192 by 108 may work). Then, I would have used the jpeg (or png) export option. Set the width/height to 1920/1080 (You don't want the final image to be larger than what your screen needs, that eats up extra computer memory for no good reason), then make sure "crop image to aspect ratio" is OFF and "restrict to map border" is ON. For a better quality image, you can turn on a bit of antialiasing, 67% equals the quadrupling of image size you had manually specified in your screenshot. Now, just save the image and it should be in the appropriate format.

That's intentional for the traveller symbols. The gas giant symbol isn't a primary planet in it's own regard, it is an indicator that a gas giant is present in the system, just as with the bases, and other information, basically just a modifer for the main planet symbol.

Just a general comment about live streams, YouTube always needs to process them after they are done, so it is out of our hands when the video will appear, but usually it will be a couple of hours after the stream ends.