Well, you gotta remember that "as official as possible" can still mean unofficial. I mean, even though Arch is updating 6, it's still gonna be considered a fan-hack.
Also, I have a question: you said you're importing updated mechanics, but what about animations? I know that the mercenary and archer animations in 6 are very...well, different compared to the ones in 7 & 8. And the Sage animations have no sound when they're casting the spells, either. I think including that would be good, but you can leave it as is. I wouldn't mind, it's your hack after all :P