Hiya voBerry, play nice, Garfield was trying to help.
(a few minutes on google would have answered most of your questions)
1) Garfield was spot on for & so are you, log into the Vodafone BIS portal & change it in there.
2) The only way without a 3rd party app is to put the phone into silent mode.
3) Before swapping out make sure you power it off, not only to stop damage, but to flush the write cache. usually media files (video, music, pictures, etc) are stored there (but this is changable), but mostly it depends on what you copy on there when you conenct it to your PC. Apps generally aren't stored there unless you are given the option to chose this during an install.
4) ~860Mb (goto Options->Memory
5)
View Document
6) I believe there's Third party apps that can do it
7) Garfield kindly answered this one.