The most deadly text-related sin I guess in any presentation, is where the text displayed moves the focus of your audience away from you and the topic. I've see

The most deadly text-related sin I guess in any presentation, is where the text displayed moves the focus of your audience away from you and the topic. I've seen enough presentations where the speaker is usually just re-reading the text on the display. That to me is not presentation, but rather becomes a reading class.