no, you don't need to install cIOS to run homebrew.
You need one to play games from USB.

if you don't plan on playing games from USB, then you don't need cIOS.


rev20b is OLD.
don't follow random old outdated tutorials.
Do you need this specific version? why 20b instead of 17 or 21?

The latest version is rev21 d2x v10 (NOT v6. the link above if also from an old FAQ)

99% of users are installing cIOS because they hack their console to play games from USB.
I'll just assume you also want to play games from USB, then you need to install cIOS.

1. don't install an old version. (I understand that you think the guide you found was the way to do things, but look at the date of the guide)
2. read a lot, be sure that what you are doing is the updated and correct way to do it.
3. ask if you need help before acting.

 

Playing from USB, and playing from disc are two different things.
Playing from Disc is more invasive and requires that you change almost all your system files. I wouldn't personally recommend this, it can be a cause of many problems. don't use DarkCorp/cIOSCorp/PimpMyWii. He will only have issues in the future.


Playing from USB is so much easier, faster and convenient (all games listed on screen, no need to burn discs and go to the console to switch them, many many options like region free, video mode, language selection, cheat codes, automatic anti-piracy patches, etc.).
But, I guess it's personal preferences.

For USB loading, you only need to add 2 (or 3) patched system files (cIOS). It doesn't touch existing ones.
d2x cIOS v8 or v10 is recommended.
slot249, 250 and 251, using respectively base 56, 57 and 58.



For the region free, it depends what you want to do and launch.
Wii game image or channels from USBLoaders: nothing special required when launched from a loader. like I said, it's so much more convenient to use a loader and USB than the game disc. it has automatic region free.
Wii games Disc or channels from system menu: you need to patch your system menu. It's done temporarilly by a Disc loader (like GeckoOS, or wiiLauncher), or always at launch by Priiloader (keep reset pressed when you boot to see if you have priiloader installed, go to the settings and enable region free all).
For the channels, you from system menu, you will also require to patch your IOS used by the system menu. it can be dangerous if something goes wrong. Always make a NAND backup before editing your system files.