Hi Tony,

See answers inline

Maybe, although I am not sure how.  Then again, my knowledge of the DataGrid is limited

Yes

Yes

If you can, I would recomment using the DataGridView instead of a DataGrid as it is much easier to configure and manipulate.

Using a DataGrid:

        protected override void OnLoad(System.EventArgs e)
        {
            DataGrid grid = new DataGrid();
            grid.Dock = DockStyle.Fill;
            this.Controls.Add(grid);

            DataTable table = new DataTable("Table");
            table.Columns.Add("Id", typeof(Int32));
            table.Columns.Add("Name", typeof(String));
            table.Columns.Add("Hidden", typeof(String));

            DataRow newRow = table.NewRow();
            newRow["Id"] = 0;
            newRow["Name"] = "Zero";
            newRow["Hidden"] = "Don't display";
            table.Rows.Add(newRow);

            newRow = table.NewRow();
            newRow["Id"] = 1;
            newRow["Name"] = "One";
            newRow["Hidden"] = "Don't display this either";
            table.Rows.Add(newRow);

            grid.DataSource = table;

    // Styling a grid is done using Table- and ColumnStyle objects

            DataGridTableStyle tableStyle = new DataGridTableStyle();
            tableStyle.MappingName = "Table";

            DataGridTextBoxColumn colStyle = new DataGridTextBoxColumn();
            colStyle.MappingName = "Id";
            colStyle.HeaderText = "Id";
            colStyle.ReadOnly = true;
            tableStyle.GridColumnStyles.Add(colStyle);

            colStyle = new DataGridTextBoxColumn();
            colStyle.MappingName = "Name";
            colStyle.HeaderText = "Name";
            tableStyle.GridColumnStyles.Add(colStyle);

            grid.TableStyles.Add(tableStyle);
        }

Using a DataGridView:

        protected override void OnLoad(System.EventArgs e)
        {
            DataGridView grid = new DataGridView();
            grid.Dock = DockStyle.Fill;
            this.Controls.Add(grid);

            DataTable table = new DataTable("Table");
            table.Columns.Add("Id", typeof(Int32));
            table.Columns.Add("Name", typeof(String));
            table.Columns.Add("Hidden", typeof(String));
            DataRow newRow = table.NewRow();
            newRow["Id"] = 0;
            newRow["Name"] = "Zero";
            newRow["Hidden"] = "Don't display";
            table.Rows.Add(newRow);
            newRow = table.NewRow();
            newRow["Id"] = 1;
            newRow["Name"] = "One";
            newRow["Hidden"] = "Don't display this either";
            table.Rows.Add(newRow);

            grid.DataSource = table;
            grid.CellFormatting += new DataGridViewCellFormattingEventHandler(grid_CellFormatting);

            grid.Columns["Id"].ReadOnly = true;
            grid.Columns["Hidden"].Visible = false;
        }

        // each cell will call this method before drawn
        void grid_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
        {
            if (e.Value != null && e.Value != DBNull.Value && e.ColumnIndex == 0)
            {
                if ((int)e.Value > 0)
                {
                    e.CellStyle.BackColor = Color.Green;
                    e.Value = "+" + e.Value;
                }
                else
                {
                    e.CellStyle.BackColor = Color.Red;
                    e.Value = "-" + e.Value;
                }
            }
        }

Using a DataGridView, you can easily substitute the DataTable with a List<T>, something I could not get to work with the ColumnStyle objects on the DataGrid.  Then again, this is quite possibly due to my lack of knowledge.