Hi
I am using Ubuntu + Xfce.
And I have a few questions:

1)  I want to add sound "monitor" (to show the volume) to the panal.
     How can I do that?

Do you not have the indicator plugin on the panel? It show show the default ubuntu sound indicator. Right-click the panel, select Panel->Add New Items, and add the Indicator Plugin. If that doesn't work, you can always add the Mixer plugin.

1)  I want to add sound "monitor" (to show the volume) to the panal.
     How can I do that?

2) I configured the "Change layout keys" to Alt + Shift.
    from some reason, this configuration doesn't saved.
    after log out I need to configure this again.
    How to fix it?

TNX