First. The Kansai problem. I am not sure if boston would fit either. More or less, it's a less refines, more gruff, kinda rough around the edges dialect. Sadly, if it'd be anything, maybe Ebonics

But agian, I don't think I would like Mitsune speaking ebonics any more than the southern accent.
Secondly, I enjoy plenty of dubs. Beefmaster hates my cuts appearently just because I have good reasons as to why I don't like dubs. He will stick up for dubs always. I on the other hand find the following dubs to be quite well done:
Cowboy Bebop
Ghost in the Shell
Gundam Wing
Tenchi
Lain
Dragon Half
Excel Saga
Galaxy Fraulein Yuna
Project A-Ko (1)
Giant Robo
Akira (Original and new dub)
Irresponsible Captain Tylor
My list is not limited to those titles, that's just the first ones that came to mind.
Again, take it from someone who doesn't prefer dubs or subs, just prefers QUALITY! (That being me) - The Love Hina dub is HORRID! The DVDs are of course still worth buying since the show is that damn good.... but I just can't lie and say the dub is good. It's not.
Third. The Suu problem. Actually, it didn't say who colonized the island. It could have been colonized by Indians, but given that its location is southeast of Japan, it's not likely. I would think it to be more Indonesian. Maybe even just darker skinned orientals (Much like the Koreans, Japanese, etc...) In any case, Suu lives in Japan and speaks Japanese. In fact, she speaks with a Kansai dialect. Since the dub makes it that everyone in Japan speaks English, she would probabyl have a similar accent to Mitsune. (Which I would hope is not Southern Belle or Ebonics.)
Any other questions or slanders? I like em!