What is the best anti-brick tool I should install for the vWii?
None, because they don't exist;I was wondering this as well.
The best strategy is to start ftpiiu-everywhere in WiiU mode and make a file-level backup of the slccmpt01 (Vwii) partition (or make a block-level backup - nand.bin + keys.bin): from there you can always copy back system files if you uninstall/overwrite a critical title, or manually remove a title's folder if you bannerbrick