That is an interesting use case. If I have interpreted your post correctly, you want to boot from a flash drive into a generic default OS or a persistent and encrypted / password protected OS. Doing that on one operating system is quite difficult as far as I know. However, you could dual boot two Fedora installs on one drive (I chose it because it’s what I use and I remember that you can set up encryption in the install. You could use whatever.). Basically, flash the installer to the drive you want to use, and to a second drive. Boot into the second drive and flash fedora onto the free space in the first drive, and enable encryption when prompted. The installer is a live boot (at least on the KDE spin) and will functions as the amnesic one. The other will be password protected and remember changes.
As far as I know it wouldn’t, but Kamala is VP, so if he resigned she would be the 47th president for the remainder of Biden’s term. The joke is that the trump merch says 47 but now it would technically be 48 and they’d have to make new stuff.