Dawn of War has been started, and any of the people here interested can sign up <shameless plug>. It is not shattered no post appocolyptic thing going on. With a few understandings the characters can even be transfered.
1) This would be considered an alternate time line, and the events of 5/8 would not have transpired.
2) Anything the characters do in dawn does not affect 5/8 at all and vice versa.
3) Level would be a bit more moot in Dawn.