It's safe and it has a good purpose, but there the community rates the sites so some ratings may be inaccurate and subjective.
Here you can convert PNG images to ICO icons and vice versa. It's safe, but converted icons are publicly visible.
It's safe. However, it's now useless because all modern browsers include popup blocker.
Protection against spambots. You've probably already seen it: you had to retype two words from the image.
VideoLAN is an open-source organization that made VLC Media Player. Website and software are safe.