While wearing iron boots, it is possible to open chests underwater after using the hookshot on something it can grab onto. By utilizing this, the longshot can be obtained and the water does not have to be raised back to make it to the boss key or boss door in a glitchless speedrun.
Although the blade traps in this room move much faster than they did in the original OoT, there is still no need for the longshot to get past them. Instead, simply equip the hover boots and use some well-timed rolls to get past them. Because of the way blades traps give damage, the wall timed rolls will give you a sort of invincibility against them, allowing you to move right through them. A superslide will also suffice.
Unlike in the traditional OoT, you do not have to do a hover in order to skip this dungeon's boss key. Instead, you can use the hookshot towers that conveniently appear once you hit the crystal switch about the door. Climb on either one of these towers and position yourself flat against the wall. Now do a sidehop immediately followed by a jumpslash to clip through the boss door.