Apologies - only now I have noticed that you have asked for VB.NET code, not C#. Here is the same thing in VB.NET:
Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
    Dim argumentsList = New List(Of DAItemGroupArguments)()
    For Each control As Control In Me.Controls
        Dim itemId = TryCast(control.Tag, String)
        If itemId IsNot Nothing Then
            argumentsList.Add(New DAItemGroupArguments("", "OPCLabs.KitServer.2", itemId, 50, control))
        End If
    Next control
    Me.easyDAClient1.SubscribeMultipleItems(argumentsList.ToArray())
End Sub

Private Sub easyDAClient1_ItemChanged(ByVal sender As Object, ByVal e As EasyDAItemChangedEventArgs) Handles easyDAClient1.ItemChanged
    Dim textBox = TryCast(e.State, TextBox)
    If textBox IsNot Nothing AndAlso textBox.ReadOnly Then
        If e.Exception Is Nothing Then
            textBox.Text = e.Vtq.DisplayValue()
        Else
            textBox.Text = "** Error **"
        End If
    End If
End Sub

Private Sub writeButton_Click(ByVal sender As Object, ByVal e As EventArgs) Handles writeButton.Click
    Dim textBox As TextBox = Me.writeValueTextBox
    Me.easyDAClient1.WriteItemValue("", "OPCLabs.KitServer.2", CStr(textBox.Tag), textBox.Text)
End Sub

Yes. You can have a look e.g. at following examples in the Bonus Pack:

HmiScreen
SubscribeToMany

For illustration, below is a relevant piece from HmiScreen example. It uses a "tag" string configured on form's controls as ItemID, and subscribes to every such item. It then reacts to item data changes and updates the controls with the new value.

I hope this helps.
Zbynek Zahradnik

private void Form1_Load(object sender, EventArgs e)
{
   var argumentsList = new List<DAItemGroupArguments>();
   foreach (Control control in this.Controls)
   {
      var itemId = control.Tag as string;
      if (itemId != null)
         argumentsList.Add(new DAItemGroupArguments("", "OPCLabs.KitServer.2", itemId, 50, control));
   }
   this.easyDAClient1.SubscribeMultipleItems(argumentsList.ToArray());
}

private void easyDAClient1_ItemChanged(object sender, EasyDAItemChangedEventArgs e)
{
   var textBox = e.State as TextBox;
   if (textBox != null && textBox.ReadOnly)
   {
      if (e.Exception == null)
         textBox.Text = e.Vtq.DisplayValue();
      else
         textBox.Text = "** Error **";
   }
}