You have 2 options to install TB2K:

1. Use MultiInstaller to install TB2K and TB2K patch
2. Manually apply the TB2K patch:
   1) Copy the contents of SpTBXLib\TB2K Patch folder to TB2K\Source folder.
   2) Run tb2kpatch.bat

At designtime just set the Caption property in the Object Inspector.

The item should be placed on a TSpTBXToolbar with Stretched setted to True, and ShrinkMode setted to tbsmNone.
Just set the item's Anchored property to true, you can use the CustomWidth and CustomHeight properties to set the initial size value.

The item should be placed on a TSpTBXToolbar with Stretched setted to True, and ShrinkMode setted to tbsmNone.
Just add a TSpTBXRightAlignSpacerItem above the item.

The control should be placed on a TSpTBXToolbar with Stretched setted to True, and ShrinkMode setted to tbsmNone.
Drop a control on the toolbar and set the control's Align property to alClient or set the Anchors property to include akRight.

You can custom paint toolbar items and controls using this events:

• OnDrawItem/OnDrawBackground: to custom paint the item background
• OnDrawCaption: to custom paint the item caption
• OnDrawImage: to custom paint the item image icon
• OnDrawHint: to custom paint the item hint

All these events have 2 important parameters: PaintStage and PaintDefault.
PaintStage indicates the current stage in the drawing process.
DefaultDraw indicates whether the control should continue with the default painting after the event handler exits. Set DefaultDraw to false to prevent the drawing of the control after the event handler exits. If DefaultDraw remains set to true, the control continues with the default painting process.

Example:

procedure TForm1.SpTBXItem1DrawItem(Sender: TObject; ACanvas: TCanvas;
  ARect: TRect; ItemInfo: TSpTBXMenuItemInfo;
  const PaintStage: TSpTBXPaintStage; var PaintDefault: Boolean);

begin
  if PaintStage = pstPrePaint then begin
    // Override the default painting, we are going to take care
    // of all the painting here
    PaintDefault := False;
    // Paint the item in red
    ACanvas.Brush.Color := clRed;
    ACanvas.Rectangle(ARect);
  end;
end; 

You have to set the toolbar's FullSize to true and ShrinkMode to tbsmWrap.

To disable the focus rectangle painting on button controls (TSpTBXButton, TSpTBXCheckBox, TSpTBXRadioButton) use the OnDrawCaption event, the focus rectangle is painted after the caption painting is done:

procedure TForm1.SpTBXButton1DrawCaption(Sender: TObject; 
  ACanvas: TCanvas; ClientAreaRect: TRect; var ACaption: WideString; 
  var CaptionRect: TRect; IsTextRotated: Boolean; 
  const PaintStage: TSpTBXPaintStage; var PaintDefault: Boolean);
begin
  if PaintStage = pstPostPaint then
    PaintDefault := False;
end;

Use the SpFocusEditItem utility function located in the SpTBXEditors.pas unit. The first parameter is the editor item, the second parameter is the View where the item is located, normally a toolbar view:

procedure TForm1.Button1Click(Sender: TObject);
begin
  SpFocusEditItem(SpTBXComboBoxItem1, SpTBXToolbar1.View);

end;

This is not done automatically by the control, you have to create the buttons yourself, take a look at the Overview demo.
I choose to leave it to the component user because there are many ways to handle this: scrollers, buttons, popups, chevron, different positions, etc.
You can also use the TabAutofit property to resize the tabs without the need to use scrollers, like Firefox.

In Delphi, margins are used to specify the space around the control, and padding the offseting inside the control.
Padding, Margins and AlignWithMargins properties were introduced in BDS 4

The compound components such as the TSpTBXDockablePanel or the TSpTBXTabControl/TSpTBXTabSet have a Toolbar public property, access this property and use the mouse events of the internal toolbar:

procedure TForm1.FormShow(Sender: TObject);
begin
  SpTBXDockablePanel1.Toolbar.OnMouseDown := MyMouseDownEvent;
end;
  
procedure TForm1.MyMouseDownEvent(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var
  IV: TTBItemViewer;
begin
  IV := SpTBXDockablePanel1.View.ViewerFromPoint(Point(X, Y));
  if Assigned(IV) then
    Caption := IV.Item.Name;
end;