1. You can backup system settings, email, and documents. Applications can't be backed up... yet.

2. The MMC card is just for storage really, unless you choose to boot off of it. It is my understanding that if you choose to do this, you can backup the MMC in a working state, and if you blow things up you can just restore the MMC backup and you'll be all set again.

Also, you can use some of the MMC card as swap. Which helps greatly on the 770 (essentially an extra 64mb of virtual memory, keeps stuff from crashing.)

3. Opera is the best bet really. Make sure you update your 770 to the latest OS.

There is MiniMo available, and while some like it... I think its kind of a mess. But it does let you get to places Opera can't go.