Have a new DSi and using a M3i Zero to play backups. I want to know what I should be careful of so I can get the best usage of this system.

I assume I should avoid updating the DSi firmware online or with new games, is there any way to permanently block this?

Do Nintendo have any silent background updates I should be aware of?

Is it ok to surf the net on the DSi with the card inserted or should I remove it?

Anything else along these lines I should know?