TRichView.com

Yes to 2-5, but I am not sure that do you mean in 1.
Do you want to insert text to be displayed at the specified X,Y coordinates? If yes, it is not possible. Text is positioned according to text flow in preceding paragraphs.

Yes, of course it is possible to insert in the position of caret. You can insert text, or picture, or table, or file (text/RTF/RVF), or stream (text/RTF/RVF).

1) You can use hyperlinks, OnJump event occurs when you click a hyperlink.
or
2) You can use OnRVMouseUp event. In this event, you can use GetItemAt to get the item below the mouse pointer. If this is a text item, this method also returns an index of character below the mouse pointer. So you can use it to find a clicked word.