Which video player can I use to play the video files?
I recommend using the VideoLanClient, which runs under Windows, Linux and Mac - just as HeldenViewer. You can download it at http://www.videolan.org/vlc/.
Howto add favorites?
There are two possibilities: You can either rightclick on the favoritelist and select "Add favorite" (to type the name manually) or you search for videos with a keyword and then rightclick on an author to add it.
Why do I keep getting an error for my own edited favorites?
Are you really sure that the author has exactly this name? Please try to search for the name with the video keyword search as you may have misspelled the name. Most likely a video of the author you wanted to add will appear and you can then add the correctly spelled author.
Can I get the videos of a favorite quickly?
Just double left click a favorite of your list, then the newest videos will be shown, all new videos will be marked in yellow.