Hi!
I'm a spanish girl and I have read LOTR in spanish and english. I think that
the translation to spanish is quite good, except some sentences and words, but
as a whole the spanish book is fantastic. You have reason about the appendix.
You can find all appendices in a separated book, or inside LOTR, depend on the
edition and if the book is a paperback or with pictures.
About the translations of the names, I'm agree with you that Barbol (Treebeard)
is a fantactic name, or Ella-laraña (Shelob)and more...
In Spain, CentralAmerica and SouthAmerica there are a lot of persons that have
read the books in English, because we are huge fans of Tolkien and his books,
and for us it's very important the reading of the books in their original
language.
If you want continue learning spanish and enjoying with the books, I recommend
you the web page elfenomeno (inside "Community" you can find the address).
Regards from the south,
(Saludos desde el sur)
gilraen_egr
PD: I'm so sorry about my poor english (the prepositions are horrible! ;-)).
Next time I'll write
better.