Nosferatu is public domain, so it is free to anyone who wants it.
A soundtrack for Super Castlevania IV has never been released officially. The game has been out-of-print for 15 years now. The score is only one element of the game, so I personally think it could be utilized under fair use laws.
If Jay or a moderator can give me a ruling on this, I would really like to post direct links here to the finished product, if possible, to make it more readily available to anyone who wants it.