there is nothing wrong with your NTLDR or your external drive.
Think about it. you know those are error messages, right? But they are only error messages when they are being showed to you, not when you go looking for them in the files that contain them!
Your logic here would be similar to performing a binary dump of a executable file such as diskcomp, and because it shows "Disks Compare OK" assuming that any floppies you happen to have in your drives are identical. You're seeing the messages, but you are basically seeing where the program loads those messages when it wants to show them because they are relevant; seeing them in a disk dump doesn't suddenly make them relevant!
What you are seeing is the binary dump of the boot sector itself. Why you would have a bootable external drive I haven't the faintest, but what is relevant here is that unless you are planning on installing the drive into a computer and booting to it, it's rather pointless to lose any sleep because it has a boot sector. NTFS drives do not require NTLDR. NTLDR is the core component used during the windows XP and earlier boot process.
