Is it possible to fork Bitcoin and solve the following problems?
I don't see quantum computers a threat for bitcoin and with recent changes in Taproot protocol it will be possible to protect against that, if it ever happens.
If this thing ever happens it would affect all military grade encryption, banks and everything else that don't have protection for that.
How to secure the SHA256 encryption and make it immutable to QC attacks?
SH256 algorithm is secure enough for most cases, SSL Certificates is using it for all websites today.
I am pretty sure, Satoshi Nakamoto must have thought about the possible problems there has to be a solution, but exactly where?
He was not prophet to see what will happen in future on every aspect related with Bitcoin, including quantum computers.