For one, stability has nothing to do with fragmentation. And the second thing is: fragmentation was actually one of the plus points of NTFS compared to competing file systems. Also fragmentation is unavoidable under all file systems.
Some file system drivers do background defragmentation, but that doesn't mean that those file systems don't get fragmented - actually, if you think about it, it means the very opposite, ie. that they get very fragmented, and hence the need for continuous defragmentation in the background. And Windows now also does automatic and periodic defragmentation of NTFS volumes.
Again, this is a non-sequitur. The source being closed has nothing to do with the speed at features are added. And just because something is open source doesn't mean that it magically develops itself at an insane speed. Instead the speed at which something evolves is determined by how expectations evolve and how much manpower is actually thrown at developing it. Regardless of whether its source is open or closed.
It's slower on Linux because there's less manpower thrown at the Linux implementation of the file system driver, not because of any particular property of NTFS.
No, it's not. It's dependent on the file system driver providing atomicity. But it does not need the file system to be NTFS, because it uses no feature that's somehow specific to NTFS.
Like PM wouldn't be a totally new thing to PCs.
