So if they are seriously really close to each other, the sword is much longer than Sasuke's width, so the sword would end up spawning in Naruto? But through BS it would move a little bit backwards (a lot backward actually) from Sasuke's original position? Or are you trying to say the tip of the blade would appear where Sasuke was somehow, even though logic dictates that it would at the very least be the center of the sword?
The blade won't appear in Naruto. It would appear in front of Naruto (thats assuming Sasuke was in front of Naruto). Since Naruto can move faster than the blade and has faster reaction that mean he is capable evading the blade.