Well, I guess it doesn't take long to PL your sections, so it's not that big of a deal for me. But I'm curious what is making it so difficult? You're not trying to edit in just the one word, are you? If you record the whole phrase or sentence and paste that in, you should be fine. I wouldn't worry too much about matching the sound just right either, since there'll be so much other speech in between your parts.
That being said, if you really want to do the whole thing over, it's up to you. But I know you have plenty on your plate, so I'd hate for you to take extra unnecessary work.