Hi, everyone, first time I post. ^_^
Anyway, brace yourselves for a post from someone who has given it too much thought altogether:
On the subject of "Jaguar D. Saul", I'm afraid that, as a native Spanish speaker who also knows some Japanese, I have to contradict. The katakana reads "haguwa-ru", which would translate into something like Hagwar, or even Hagwal. But if you're trying to say it's the Spanish "jaguar", even though the "j" sounds like an "h", the lexical stress doesn't fit. I'm assuming most of you stress the first "a" of the word, that is, you pronounce "jaguar" in English with an "h" instead of a "j". But in Spanish it's the last "a" that's stressed. If I were to render the word "jaguar" in katakana I'd just write "hagua-ru", which stresses the last "a" enough, but Oda has inserted that extra "w" after the "gu", shifting stress to the first syllable and ruining the Spanish pronounciation. My first reaction to his name was "He can't possibly be called Hogwarts…" then I blinked and looked again xD
As to Nico Robin's attacks, I haven't seen the katakana yet (I only started reading One Piece scans last year), so I can't say. Nico certainly has that Latin feel to her, but, why would Oda use Spanish numbers next to the French "fleur"? That is, unless it's not supposed to be "fleur" but "flor"...
Anyway, thanks for listening to my ramblings. xD