All I need is a simple text editor that is able to do simple formatting (bold, italic, underline, list).
Given my situation, what is the best solution for editing RTF in linux?
LibreOffice Writer can be used on rtf files. You can read more about it here.
For the CLI use catdoc. Since this is superuser.com I'm assuming you know how to install it. For a GUI approach I know LibreOffice can view .rtf, but I also think Abiword will work.