If you mean the middle screenshot here: http://2.bp.blogspot.com/_9bGkC0sN23w/Si9_AJEoijI/AAAAAAAAAE4/WJS4ohrRttY/s1600-h/DepthPrev.png , thats not the music selection area, its the area that comes up when you tap the top right hand button on the Now Playing screen. It shows the other music in the album. Thats what is changed.
ALT images are alternate images for the player. Yeah, they're pretty useless but leave them in there. :P
Sometimes, the folder you download isn't the folder you want to SSH in. Open the folder you downloaded, and if there is another folder called "Depth" or something ending in .theme, then thats the folder you want to SSH. This sometimes happens to me, but you just gotta SSH the right folder in. :)
No. You can make it so your system strings are edited yourself so your slider text and power off text can say whatever.
The easiest way to get screenshots off your iPod is to connect your iPod to your computer, open up my computer, click on you iPod go to Internal Storage>DCIM>999APPLE and all your screenshots should be there