This is the best plugin I know: https://www.youtube.com/watch?v=rOGToozLl1Y&t=2m24s
Adding metadata is useful only for previews, because very often customers download a bunch of preview files and then they don’t remember from who. So if you add to mp3 tags of your preview file the track’s title and your profile URL – http://audiojungle.net/user/ianpwilliams it will help customers to identify your work when they want to purchase it.
Anyway, Adobe Audition allows you to tag WAV files.
Series is a chronological sequence of episodes that share the same topic. All things in the series (eg episode, edition) must be connected. As long as your videos are dedicated to games, you are covered by a standard license for one year or 52 episodes, whichever comes first.
I don’t think the word “good” applies to any Eurovision song.
On some other markets it’s mandatory to credit the author and licensor, unless the nature of the project does not allow that, like a TV commercial, for example.
Don’t be shy to charge him for your time.
JFYK – you don’t have to be exclusive to get an item featured.