The ASCAP and BMI databases are a good place to start; from there you'd need to try the national library of the country in which it was written, and after that, Google.
Such "orphan works" are a known problem, but periodic legislative action has yet to make satisfactory progress on dealing with it.
If someone is searching for information about DWI songs, there is lots available of information available on the internet. One can find lyrics to their songs, videos that accompany them, as well as who wrote and performed them.
Which one? There appear to be at least three songs by this name.
Various songs are controlled by various companies and individuals.
Warner Tamerlane and Sony/ATV Songs.
mp3humgama
Northern Songs
Unless the songs from iTunes are you own work or you own the copyrights you will not be allowed to put them on YouTube. The advice from YouTube says: Posting copyright-infringing content can lead to the termination of your account, and possibly monetary damages if a copyright owner decides to take legal action (this is serious-you can get sued!).
Yes; generally they are controlled by the game production companies unless other arrangements were made.
Since indie music does not always have up-to-date information on songs, it is truly impossible to know how many songs are titled Beautiful. Currently on Itunes, there are over 200 songs available for purchase with this title.
There are too many things by that name to list--movies, television shows, songs, etc.
Some are Music Sales Group, some are EMI Longitude, and some are other publishers or administrators.
It varies, based on who received a composer credit, but a significant majority are controlled at least in part by EMI April.