Normally, I can use Alt + Tab to switch between windows where pressing the Tab key repeatedly takes me to the desired window. Is it possible to use the mouse to select the window I want to switch to?
With many open windows this would be way faster than pressing the Tab key many times.
I have thought of the same thing, but as far as I know it is not possible with marco, maybe compiz?
I have a bash script with yad UI for that on my computer. Will post ih here when I get back home.
Here 
You can create a panel launcher and launch the script from there.
Dependancies: xdotool wmctrl, iconv, convert, yad (version 0.38.2 or higher)
Selecting the window in the list will give that window a focus.

You can also change the temp dir for the icon cache
in this line https://gist.github.com/Misko-2083/3a360a1f2d913154e6384a88b1ca6d49#file-wlist-sh-L100