You should stop by HERE first, the mods will give you links to answer almost any question you may have.
That is a lot of questions there! You will need to know what your system menu is to choose the correct method of installation. There are guides on this site to mod whatever version it is that you have (look at the links in my sig). Not likely to brick your wii as long as as you are following directions. You can still play online, just don't cheat! Just installing HBC is not going to harm your wii. Do some research on this site and you will be fine.