

Images patched by Rufus can definitely pass secureboot, as long the bootloader wasn’t touched. Secureboot only checks the signature of the bootloader, not every single file of the operating system, otherwise it will take hours to boot
Plus Rufus touches some XML read by the installer, doesn’t crack the executables





If the password is long 15 characters that means you use a password manager. At that point just put the bitlocker password in the password manager