Movement of text on the TForm without blinkings

[Deiv]

Good Morning,
The following code has a effect to redraw a text in movement on any object of the TForm; this it works perfectly, but if I introduce a TImage (background) in the TForm, Delphi shows me an error in this line: 
Border: = BorderWidth + 3;
ERROR
raised exception EAccess Violation

Code:

       PaintTo (Bitmap. Canvas, Left, Top);//Draw the border
       => Border: = BorderWidth + 3;
       BitBlt (Bitmap. Canvas. Handle, Left + Border, Top + Border, Width - Border * 2, Height - Border * 2, Canvas. Handle, Left + Border, Top + Border, SRCCOPY);//and the content

Code:

unit MIMOuse;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ExtCtrls, StdCtrls;

type
  TForm1 = class(TForm)
    Timer1: TTimer;
    Button1: TButton;
    Memo1: TMemo;
    procedure FormCreate(Sender: TObject);
    procedure FormPaint(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  Step: Double=0;
  Bitmap: TBitmap;
  Circle: array [0..255] of TPoint;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
 Timer1.Interval := 33;
 Bitmap := TBitmap.Create;
 Bitmap.Width := ClientWidth;
 Bitmap.Height := ClientHeight;
 Bitmap.Canvas.Brush.Color := Color;
 Caption:= 'The New custom Cursor ';
end;

procedure TForm1.FormPaint(Sender: TObject);
var DestDC: Cardinal;
begin
 DestDC := GetWindowDC(Handle);
 BitBlt(DestDC, ClientOrigin.X - Left, ClientOrigin.Y - Top, Bitmap.Width, Bitmap.Height, Bitmap.Canvas.Handle, 0, 0, SRCCOPY);
 ReleaseDC(Handle, DestDC);
end;

procedure TForm1.Timer1Timer(Sender: TObject);
var
 Size: Double;
 Value: TPoint;
 Index, Border: Integer;
begin
 Size := 360 / Length(Caption);
 with Bitmap.Canvas do
  begin
   FillRect(Classes.Rect(0, 0, Bitmap.Width, Bitmap.Height));
   for Index := 0 to ControlCount - 1 do
    with TWinControl(Controls[Index]) do
     if Visible then
      begin
       Repaint;
       PaintTo(Bitmap.Canvas, Left, Top); // Draw the border
       Border := BorderWidth + 3;
       BitBlt(Bitmap.Canvas.Handle, Left + Border, Top + Border, Width - Border * 2, Height - Border * 2, Canvas.Handle, Left + Border, Top + Border, SRCCOPY); // and the content
      end;
   SetBkMode(Handle, TRANSPARENT);
   for Index := 1 to Length(Caption) do
   begin
    with Circle[Index] do
     begin
      if Index < 1 then
        Value := Circle[Index - 1]
      else
        Value := ScreenToClient(Mouse.CursorPos);
      Inc(X, Round((Value.X - X) * 0.6));
      Inc(Y, Round((Value.Y - Y) * 0.6));
      TextOut(X + Round(66 * Cos(Step + Index * Size * (Pi / 180))),
              Y + Round(66 * Sin(Step + Index * Size * (Pi / 180))),
              Caption[Index]);
     end;
    end;
  end;
 FormPaint(nil);
 Step := Step - 0.06;
end;
end.

First.- How to solve this problem?
As Beginner  I have tried to solve this way: 
I have placed a TPanel (property Align=AllClient) as background of the TForm and east in turn contains (inside) a TImage (property Align=AllClient; stretch= true), the effect works normal but slowly, and it has a problem with the repainted, that is to say a lot of TWINKLING and slowly. 
I need to place in this code a TImage as background of the TForm and I need that it works without twinklings. 
Second.- How to implement (to solve) this code when introducing a TImage in the TForm so that it works without twinklings?