Wallpaper flickering
Thanks for the Console log:

I see two item making problems with the User Interface (UI) in (WindowServer)

One is the VLC.app and the second one is the "Transmit application"

I know what is VLC app, so just disable (remove) it to test. (then download updated version)

Second one "Transmit" you know what it supposed to do but it is making problems. See if there is an update  or disable it.