Is it possible to create a single Action that would:
Copy "ARTIST" tag to "BAND" tag unless there is more than one "ARTIST" per "ALBUM", and if there is more than one "ARTIST" per "ALBUM", enter the words "Various Artists" into the "BAND" field"?
That would require reading and comparing the ARTIST tags of all files in an album. As far as I know, that isn't possible. Each file is treated seperately.
Yeah, thanks for the reply. After I thought about it for a while, that occurred to me, so I had my doubts that it would be possible. Too bad for me! 
That could have saved me a lot of hassle....