iPhone stuck on boot screen
A "no-erase ipsw" is used when you want to go from a jailbroken device to iOS without losing data. In your case, you are already on iOS and seeing as how you have eliminated all of the potential software fixes, you most likely have a hardware issue.

Depending on the problem, the data may be recoverable but it would have to be looked at by a repair shop that specializes in iPhone data recovery.