Just wondering if this is an "o.k" thing to do and will not mess with the Unity project?

Are there any issues with doing this?

I wanted to use it to store per-project default settings for an AssetPostprocessor class I'm making. i.e:

[ System.Serializable ]
public class TextureAtlasImportSettings : ScriptableObject {
/// data goes here
public static TextureAtlasImportSettings GetDefaultTextureAtlasImportSettings()
{
    string libraryPath = System.IO.Path.GetDirectoryName( Application.dataPath )
                                                                 + "/Library/";
    string settingsPath = libraryPath+"DefaultTextureAtlasImportSettings.asset";

    TextureAtlasImportSettings settings = (TextureAtlasImportSettings)
         AssetDatabase.LoadAssetAtPath( 
          settingsPath,
          typeof(TextureAtlasImportSettings) 
         );

    if ( settings == null ) {
       settings = CreateInstance<TextureAtlasImportSettings>();
       settings.name = "DefaultTextureAtlasImportSettings";
       AssetDatabase.CreateAsset( settings,settingsPath );
    }

    return settings;
}
}