When working with AutoCreateColumns = false, for the InsertionRow to
function property, you will need to manually set CellEditors on the
Columns.
e.g.:
<Column CellEditor="{x:Static xcdg:CellEditor.TextBoxEditor}" />
As for your second question, you can find the answer in this thread.
Technical Writer - Xceed Software
Of all the things I've lost, I miss my mind the most. - Mark Twain