Check out this youtube channel, it has a lot of great info
The Daily Note II/3 - YouTube
As for widgets on the lock screen, that option goes away when you have a passwork or the phone locked
Changing the icons on the bottom of the home screen
Just press and hold (called long press) on the icons and you can replace them with different apps. If you want different icons for the apps already there, you need a new launcher (like Go launcher) and an icon pack
As for changing the shutter sound.
Open the camera
Press the gear icon, more will show up
Press the gear again, you'll see a camera, camcorder and general settings menu
Press the gear again and scroll to the bottom
Here you can disable the shutter sound