Just some notes on the names:
- Kaito has official kanji for his name, so it should remain Kaito, rather than Kite. It's also recognized as Kaito on
http://www.behindthevoiceactors.com/video-games/Shining-Blade/
- Amil/Amyl doesn't appear to come from Norse mythology but is listed as Amil on the site. Amyl isn't necessarily wrong.
- Fafnir and Baldr are names from Norse mythology.
Fafner isn't a valid spelling for Fafnir, but the katakana is ファフナー rather than ファフニール, so I can understand using Fafner instead.
Baldr on the other hand uses バルドル, which is consistent with the actual katakana for Baldr, the Norse god's name. Balder is an uncommon spelling and is not recognizable to the extend that Baldr or Baldur are. I'd say let them use Baldr or Baldur rather than Balder, though it is listed as Balder on that site.- As for Aira, there is a river in England called Aira. Its name comes from Old Norse, so Aira would be the correct spelling. It's also listed as Aira on that site.
- Jin-Crow is the recognized spelling of his name in English, specifically in places listing his voice actor:
http://www.behindthevoiceactors.com/characters/Shining/Jin-Crow/
I disagree. Amyl is just plain wrong. There is no evidence to support this version, whereas Amil on the other hand, had appear so on various sources, including the in-game loading screen, various merchandises, and if I'm not mistaken, the Shining Hearts artbook as well.
You are mistaken. Amyl is wrong.
Jinkurou is spelt in the way his name from Kanji is directly pronounced. 刃九郎 is his name in Kanji. Therefore Jinkurou is correct. It's the same as Reiji and Rage are both correct.
Oh, one more thing I forgot. Alberich comes from norse mythology as well.
https://en.wikipedia.org/wiki/Alberich