Has anyone had any issues where they've had to load numerous videos and are not able to see them once they have been published. In preview I'm able to view the videos in the browser.

Did you try uploading your content to a web server and viewing from there?  Viewing from your local hard drive might be running into security issues that prevent the videos from loading.

If the videos do not play from a web server either, check the video file links are not pointing to your hard drive.  They should be relative links that will work anywhere.