RadRichTextBox uses internal logic in order to determine the direction of the language that particular parts of the text is in. What you can set is the direction of a paragraph - using the UI this can be done using the text direction button in the Home tab (see attached screenshot). In code, you can use the method:
As for inserting hyperlinks through code, you can refer to this article for explanations and sample code snippets: Hyperlinks
I hope this helps.
the Telerik team