Yes... but I advise against skipping bootmii. I highly recommend installing bootmii as boot2 (if you can) and making a NAND backup. It is the smartest thing you can do.
Probably not. Make sure you are using the latest version (0.3.9b) and that your Wii is connected to the internet. However, I still highly recommend updating your IOS files via this guide. Since you already installed the Homebrew Channel, you can skip to the part titled Update to 4.2.