Reply To: Maintaining paragraph styles with updated .rtf

From a technical point of view, there is no ‘simply update a file’. InDesign will place this file, as if it were never in your document.

So the idea is:
1. Create a template with styles in InDesign
2. Export a file to rtf
3. The texter write in this file and use your styles
4. Update your file

If the texter use your styles and you did nothing in your document, you should get the right result.

If you want a bit more comfort, you should try wordsflow from emsoft.

Also I can recommend Anne Maries Title on InDesign/Word-Workflow at Lynda.com.

Kai