First thing is that I would suggest you think about if you really need a script as complex as celes’. If you find yourself struggling with making any changes to it you will probably not be very happy in the long run. If you can explain what you actually require and how you want your file naming to work we can probably assist you in creating a script that does just what you want and which you actually understand and can edit yourself.
Looks like the script does not deal with albums like In His Own Words which have a proper release artist but contain tracks by other artists. To keep releases together the variable %albumartist% should be used instead of %artist% for folder names, maybe check how the script makes use of this.
Sorry that this is probably not the answer you expected, but I won’t dig through this IMHO overly complex script to do any changes.