I don't remember ever getting either of those.
However, I do recall meeting Shad in the Kakariko Graveyard on my first Wii play through, and it seems that didn't happen, either.
Do you recall exactly what the letters said? Can you at least paraphrase it for me?
Fanadi Palace: - Failure at work?
- Failure in love?
Here at Fanadi's Palace we can immediately solve all these problems and more! Take your first step toward a new life and let your feet lead you down Castle Town's southwestern thoroughfare!
Impaz: Thank you so much for beating those beasts the other day. Is the girl doing well? I certainly hope so. Though there isn't much to do here, please stop in sometime!
These were in the text dumps for the game, and Impaz's is exactly how I remember it. According to Boss, you can get Fanadi's by not visiting her or getting any heart pieces (doing a 3 heart run basically, I still have yet to test this out) but he/she also says Impaz's can be gotten after rescuing Ralis... except you don't meet her until later. If my memory is accurate at all, I could have sworn I got hers later in the game. I could be wrong though.