Vista - Questions abouts WPF developpment

Hi,

I actually test WPF RC1 and I have 4 questions that I don't find answer:

1. I use a FlowDocumentReader. This control have not "FirstPage()"
method that I need (DocumentViewerBase has it). How can I go to first
page with a FlowDocumentReader control?

2. I try to save the position and the size of Window. In order to that,
I bind Top, Left, Width and Height property to my settings class like:

Binding binding = new Binding("WindowWidth");
binding.Source = Settings.Default;
mainWindow.SetBinding(Window.WidthProperty, binding);

But when I move / resize my window, settings are not updated. Why?

3. What's equivalent in WPF for "Application.Restart()" in WindowsForms?

4. I have a MenuItem defined like :

<MenuItem Name="menuCheckUpdate" Header="Check for updates"
InputGestureText="F5" Click="CheckUpdates" />

What do I write between "<Window.InputBindings>" to simply bind F5 key
press to CheckUpdates event?

Thanks very much.
Cyber Sinh