I'm not aware of any material changes between the Bestiary editions (except those incidental additions you mention).
Interesting that the "Malgash" was known as the "Balrog" in non-English editions as it's always been the "Malgash" since the first edition, as far as I know (and, presumably, the same copyright concerns would exist in any language). The Malgash even spawned a Dragon Warriors fan-site of the same name:
http://malgash.tripod.com/It's an old site, but has some interesting house-rule ideas on there that can still be plumbed for inspiration
.