iTunes tagging issues

[ProfessorKaos64]

To start off, I have 186 gigs of music, and its on a file server, so adding that library for the first time, was well exhausting. I used Mp3 tag to tag and embed album art and properly organize everything. Of course iTunes doesn't care about CD compilations like the Fifth Element Soundtrack, making me perform a search everytime I want to find it, or create a playlist from the get go as of course its by artist. After importing, it seems iTunes still has issues with some songs , like from AC/DC improperly putting it in a separate field than the rest of the AC/DC music. Is this because it didn't understand the tag data?

The biggest question I have then is: If I correct the tag data , somehow successfully, in iTunes, will those changes be made to the source files on my file server? I want to know this before I go a-fixing. Thanks [H] readers!