since you have got boot2 compatible wii no need backup or other things. now you are brick resistance!
unless you actually lunch hackmii installer and uninstall consciously bootmii as boot2!
As long as you keep boot2 you are brick resistance
Let's assume you brick it again
copy sd card files of bootmii in some low-capacity memory card (exmple : 2GB SDHC) and boomini.elf file from hackmii installer1.2. now insert it on your device power on it.
in file explorer option select bootmini.elf file (wiimote wont work in this environment only use RESET and POWER buttons on Wii for navigations and select a thing : power button navigates right direction or downward and Reset act as Select )
however when you select bootmini.elf hackmii installer lunches and you could penetrate into wii and homebrew environment and setup priiloader wii menu or missing wad or etc