New themes not displaying correctly

When attempting to use the new beta themes I'm getting display errors that seem to break the site, and the theme editing features don't seem to work. I have a more secure than normal hosting setup and I'm wondering if that's the problem, and what I need to do to fix it.

Also, installing these themes seems to have added a bunch of pages I need to delete now, perhaps a user prompt in the install process to toggle whether or not you want these pages added to your site.