OpenOffice does not handle opening RTF files very well. RootsMagic RTF files work best when used with Microsoft Word. It is best to import your RTF file into a Word Doc and then import the doc into OpenOffice.
If you are having issues with your indexes please see Knowledge Base Article: Regenerating Indexes in a Report.
The idea is to format the indexes the way you want, then do the Ctrl+A, then F9 to refresh the indexes.
(Keep in mind you can purchase older versions of Microsoft Word at reasonable prices on eBay.)