As to your questions:
1. So, you have auto-generated columns based on the data you populate RadGridView with. In order to change the default settings for any of those columns, you can subscribe for the AutoGeneratingColumn event and work with e.Column.
2. You should bind both the GridViewCheckBoxColumns to the same or related property from your bound data object. Once the bound property raises a PropertyChanged notification the value in the CheckBox column will be updated.
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