Then there is 'secure boot' which requires UEFI - in the end is less secure than an old BIOS.
Are you saying Secure Boot (using UEFI) is less secure than traditional BIOS, or that UEFI by itself is less secure than traditional BIOS? And either way, I'm curious why you think that?
Hard to say about case sensitivity. NTFS itself is case-sensitive, actually, but the Win32 layer that normal Windows apps use to access it enforces case-insensitivity (but preserves case otherwise). If the implementation here is a proper NT subsystem, then it should be able to skip that Win32 translation, and use case-sensitive operations directly. But whether it actually does so or not is an interesting question, because if you were to use that approach to actually create files that only differ by case, accessing them from Win32 world will be problematic (but possible; Cygwin knows how to do that, for example), so it may be deliberately disabled. Hopefully, it is a configurable option.
Your description is close but not quite accurate. NTFS is case-preserving: file names are stored in an exact case on disk. Case-sensitivity actually has nothing to do with what's on disk, it's a property of a given operation. And NTFS has the ability to support either case-sensitive or case-insensitive operations, as needed, on a per-operation basis. What determines whether a given operation is case-sensitive or not is a combination of 3 factors: a global system setting, the subsystem (e.g. Win32 vs Linux), and the app requesting the operation. Incidentally even if you are a "Win32 app", you can still call NT APIs directly, which negates the subsystem from the list of factors.
Why not extend NTFS to a 64-bit file system that is backward compatible w/ Microsoft's NTFS
Could you explain what you mean by 64-bit file system, specifically? Because what you said doesn't really mean anything without more context. And are you implying that NTFS-3g is not 64-bit (whatever that means) while Microsoft's NTFS is?
BLISS is ignorance.