Change background based on location/wifi

You can do this in the terminal (shell). Open the terminal and type cd ~/Desktop to change you current working directory to the Desktop.

Then for the different cases you listed:

mv *.PSD *.Ai *.INDD ~/Desktop/Workfiles

mv *.PNG *.JPG ~/Desktop/Pictures

mv *.doc *docx *.xls *.pdf ~/Desktop/Documents

mv file target is the command to move files. You can move multiple files at once: mv file1 file2 file3 target. The asterisk * is the so-called wild card character. So * stands for every character or character sequence. *.doc would mean that it would affect all files that end with .doc. You could also do it other way around, e.g., A* to affect all files that start with A.

If you want, you can copy the following lines into an empty text file and save it as example.sh and add #!/bin/bash to the first line. Make it executable by typing chmod ugo+x example.sh. Then, you can use it every time you want to move your files from your desktop by typing ./example.sh in the shell from your desktop.

So the suggested script contents would could look like this:

#!/bin/bash

cd ~/Desktop

mv *.PSD *.Ai *.INDD ~/Desktop/Workfiles
mv *.PNG *.JPG ~/Desktop/Pictures
mv *.doc *docx *.xls *.pdf ~/Desktop/Documents

As mentioned in the comments, you can save it as example.command and use chmod ugo+x to make it clickable and executable

The only way that this would be possible would be if one of the options for delay between changing wallpapers to never. When you have multiple desktops and multiple wallpapers they will have different ones but they change. If there is no never option then you might just have to set it to the longest possible or whatever is convienent. Hope this helps!