Hello,
1) Hm... I don't know how to do this... But I'll try to dig around to find the way in a next few days.
2) Label text is determined by the IListItem interface implementation. If the only thing you need is to change display name - it will be easier to inherit your own list item class from Aurigma.GraphicsMill.WinControls.ThumbnailListItem and overload GetText() method. If you need more fundamental changes - you can write your own implementation of the IListItem interface. You can find more detailed information in the
Creating Custom List Items article.
3) It depends on the type of the indicator you want to add. You can easily change thumbnail, so the simplest way is to draw some indicator on the thumbnail image itself. But if you need to add some additional control into Thumbnail List - it will be very difficult to implement, because there is no built-in support for such features.
4) Unfortunatelly we have no public additional samples for Thumbnail List. But you can
submit case - we will discuss the features which you want to see "in action" and we will correct our documentation development roadmap to reflect your requests.
Best wishes, Alex.