Sim para ambas as suas perguntas.
De Wikipedia :
The Guide to the Names in The Lord of the Rings is a guideline on the nomenclature in The Lord of the Rings compiled by J. R. R. Tolkien in 1966 to 1967, intended for the benefit of translators, especially for translations into Germanic languages. The first translations to profit from the guideline were those into Danish (Ida Nyrop Ludvigsen) and German (Margaret Carroux), both appearing 1972.
...
Photocopies of this "commentary" were sent to translators of The Lord of the Rings by Allen & Unwin from 1967. After Tolkien's death, it was published as Guide to the Names in The Lord of the Rings, edited by Christopher Tolkien in A Tolkien Compass (1975). Hammond and Scull (2005) have newly transcribed and slightly edited Tolkien's typescript, and re-published it under the title of Nomenclature of The Lord of the Rings in their book The Lord of the Rings: A Reader's Companion.
...
The Danish (Ludvigsen) and German (Carroux) translations were the only ones profiting from Tolkien's "commentary" to be published before Tolkien's death in 1973. Since then, throughout the 1970s, 1980s, 1990s and 2000s, new translations into numerous languages have continued to appear.
Eu posso falar sobre a tradução para o italiano, muitos nomes foram alterados.
Especialmente nomes de família de hobbits.