It doesnt matter if you rip hate immediatly with your first hit, the tank will take the boss back again almost immediatly if you do and at worst you'll take an auto attack, not a big deal.
Using FoF before dashing to a boss will kill your damage, as it will probably cuck you out of a gcd across the FoF window as well as you starting fof on the wrong gcd. By dashing to the boss you delay your melees reaching the boss unless they also use a gap closer (which is bad for thier damage), whereas a shield lob or provoke pull will nicely put it in the center and have the melees hit it straight away, the positioning issues also arise because after a gap closer you're in a short animation lock before you can turn the boss. This is not to mention the fact that unless mechanics dictate otherwise, having the boss in the center is usually more beneficial