There's people playing latest games on system menu 3.1 just fine. You'll probably find that some of the latest games will still not work though.
I updated to 4.0 so I could use the SD storage feature, which will come to homebrew through cIOS r14 soon apparently.
I used the following tutorial http://www.wiihacks.com/recommended-...l-working.html
I have Wiiconnect24 switched off so it doesn't like me using the shop, weather and news channel. I'm not bothered enough to do anything about it though.
As you have a mod chip and bootmii then you have minimal risk.