Slider problems aside, I noticed as soon as I added the Slider to the Slider widget area, all of my posts (which were visible when previewing before the slider) disappear and the only thing shown on the page are the header text and the slider. When I remove the Slider from the widget area, all the posts again show up in the correct location as well as the right sidebar.
Any chance these two problems I’ve posted suggest a bad Genesis install or something like that? When I first installed genesis I accidentally activated it, but then I activated the Legacy theme once installed. I assume that’s OK, that activating Genesis wouldn’t accidentally corrupt future theme activations?