Without Quotation.MdiParent = Me
, the form displayed would not be an MdiChild. It would instead be displaying as a normal form by itself. Try dragging it around the screen and you'll see that it is not confined to the MdiParent form.
See if this loads it any faster, though:
Private Sub tsmQuotation_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tsmQuotation.Click
If Application.OpenForms().OfType(Of Quotation).Any Then
Dim Q As Quotation = Application.OpenForms().OfType(Of Quotation).First
Q.WindowState = FormWindowState.Normal
Q.Activate()
Else
Dim Q As New Quotation
Q.MdiParent = Me
Q.Show()
End If
End Sub
For the second issue, select the MdiParent form and set the BackgroundImage() and BackgroundImageLayout() properties. The image will NOT display on the form at design-time, but it will be there when you run the application.