Hi,
I don't have a clue as to why your EFI is in the Root, and not a separate partition... That is the default when windows installs...
Check through the UEFI Boot Drive BBS Priorities options and see what you get..
Is your machine encrypted in some fashion... I'm wondering if the selection of a Encryption Key at Boot is part of the problem...
I don't have a clue as to why the flash drive created with RUFUS would require a password for the SSD... I use RUFUS a lot, and have never seen that before.. Did RUFUS mention anything about a password when creating the flash drive ?
One thing I have noticed with RUFUS is that sometimes when you change one of the menu options, it will cause another to change... Sometimes the FAT32 or GPT will change when you select the Image you want to use...
Also look to see if your Bios has a "Secure Boot" setting... If it does, Disable it temporarily...
BTW... You want the Legacy USB Support Enabled..