To use: Replace the MPQ with the latest patch number with the same original name with any of these MPQs in the "World of Warcraft\Data\Cache\enGB".
Launching the game through the Battle.net launcher might update the game files and remove the MPQ. If so, start it from the actual WoW program.
They do all have their original main screen animations and loading-screen wallpapers for continents and instances as they used to be (including button colors for the Wrath of the Lich King theme).
I have also included a custom change to the music, since many tracks have been replaced through the years to more unfitting ones.
Custom Music:
Filebeam
World of Warcraft:
Filebeam
The Burning Crusade:
Filebeam
Wrath of the Lich King:
Filebeam
Cataclysm:
Filebeam
You will never become banned for using these, since it does not modify the game world in any way more then changing a few animations and pictures to the login part. What they are after when it comes to editing files is cheating in the gameplay: Getting an edge over players which should not be possible.