I dumped the scripts from both the Japanese and English versions of this game and uploaded the results in an easily comparable spreadsheet. The link is: http://spreadsheets.google.com/pub?key=tO6C-0o0GrE4yT6bE0tX3bA&output=html
Difference notes: Ali is named Ruo in the Japanese.
For some reason, the line from Efreet about how to summon him is not in the English.
The Japanese gives more directions than in the English. For example, you're told that the castle is in the West after you're attacked in town, that the "hidden shrine" is behind the eastern waterfall and that the cave in Mount A=Rat (Mt. Allat) is to the north.
The name "Thor" comes from the "word," 'toa,' which refers to a spirit world where no human lives. That is where the war between Reharl and Agito was waged. It's referred to in the English as "the non-entity." The armlets, when referred to, sometimes use their function as a modifier in the Japanese. So the bearer of the Gold Armlet is referred to as "The Governing Gold Armlet," especially by the four spirits, while the Silver Armlet is referred to as "The Creating Silver Armlet." The spirits never use the Prince's name to refer to him, deferring his identity to the armlet. The Prince's name is not known to the armlet when it is picked up. It is just speaking generically to whomever picks it up. What will bring the world to ruin is actually the revival of an ancient demon by the Silver Armlet.
The conversation that the Prince overhears has a name in the Japanese. Shade's location is incidental in that conversation in the Japanese as well. This name, Kuuin, is very close to the older sister princess's name, Kuvinia... The conversation where you hear your older sister's name actually happens in reverse in the Japanese. The speaker admonishes you to go to the castle and just happens to see Kuvinia's necklace on you and then talks about it.
The forest shrine is said to be in the northwest in the Japanese, while it is in the northeast in the English.
The English is more judgmental. You're explicitly told that Agito was evil, and so is the Large Cube.
When the bearer of Silver Armlet is "freed," that person doesn't say who they are at all in the Japanese. Right before the armlet bearers are separated during the ending, the Silver Armlet does say the relationship between them (not that you don't already have a notion as to who they are...)
In the attacking instructions, the Japanese does say that a Low Kick is possible. For the "special attacks" except for the Spin Attack, it does not tell you their motions.