iPhone 5s Owner
I think I might be the first person to reply to this thread who has actually used a 5s. That is the problem, no one knows how it actually works and is scared. A few points:
1. After 48 hours your phone requires the passcode. (Noted in #96)
2. If the phone is turned off/restarted it requires the passcode.
3. To change the passcode or fingerprint, it requires the passcode.
4. If you try to reset the phone, that requires the Apple ID and password.
5. You can turn off Touch ID and just use passcode.
6. You can just use Touch ID for your iTunes password.
I have had lots of luck just looking over people's shoulder for the passcode.
It is very secure. I have never used a passcode before but am using Touch ID, it works amazingly and makes things more secure. There is nothing I am really worried about someone hacking into my iPhone for but I might as well use it, because once again with Apple, it just works.