Yeah, the correct name from the early script notes is "Windy" ("Windu" was either a mistype or the difficulty in deciphering Lucas' scribblings, for example it was "C.J. Thorpe" not "Usby C.J. Thape"). Source: the Secret History of Star Wars by Michael Kaminski.
You're right, the term "Sith" wasn't even invented by Lucas, but borrowed by him from the time of the early drafts and appears in the novelization ("Sith Lord") referring to Vader. Early on there were many Sith Knights and "Darth" was not a title, but the character's first name (originally Vader was just a "grim looking general" not a cyborg or force user). "Padawaan" was there too.
"Padme" and Pod racing were definite prequel inventions though.
Not to brag, I just finished Kaminski's book, fascinating stuff.
If Jango Fett's voice in the Prequels is going to be changed, doesn't that just reverse the situation but not get rid of the "realism problem" of accents not being inherited?
The way I figured it all these years was that Boba Fett's voice was generated or distorted by his helmet. After all, that was the case with Darth Vader and the "Bousshe" disguise Leia used. It's true the Stormtrooper helmets only distort the voice without changing it (Luke & Han in ANH). Yet in the Prequels not only does Jango's voice just get the "stormtrooper filter" when his helmet is one, it's the same with the clone troopers. Jango's helmet is noticably different than everyone else's in the movies, why not just say when the helmet goes on he suddenly sounds like Classic Trilogy Boba Fett?
Or is his voice going to sound raspy like that all the time? That might be kinda creepy to hear all those troopers talking like him (but it might be cool as hell too).
Then again there's also the possibility that Boba Fett's voice isn't the result of a voice changer OR his "natural" mature voice, but because of some hardships suffered in his bounty hunting career. Maybe his throat is scared or something from battle, or smoking too many death sticks? ;) I mean, back in the day we knew Vader had a life support system, maybe Boba needed the suit to stay alive too? (obviously Jango didn't though)
As for accents, it could be worse... you could be Christopher Lambert, who is considered French (father was a French diplomat), born in Great Neck (ha!), New York, but raised in Switzerland.