Dylan, I can't give you a complete explanation of 28d and 42a because bits aren't quite clear to me either :)
But does this help:
42a - definition is last hyphened word. Japanese is a one letter abbreviation inside another abbreviation. Not quite sure how to pass the first 3 letters.
28d - definition is last word (no letter change because its one of those 8 clues. I think it might just be a string of leads (after removing a short string) but definitely leads to the last 3 words before the definition, which should help you narrow down the word to ....well, one possible answer or its alternative spelling.