Hey, so I realize that this thread is about 2-3 years old, but I couldn't find any forum threads more recent than this. Anyways, I've been reading about this Wind Waker Barrier skip and was thinking of possible solutions.
I'm not a speed-runner; but I wonder if it's possible to use the Magic Armor to help "buffer" within the Damage Barrier & Invisible wall. I've watched the video's with the bomb's buffering damage & read some about how part of the problem has to do with the red flashing invincibility tricks don't work. However, I haven't read or could find anywhere someone making the attempt or suggesting using the magic armor.
Just sorta throwing the idea out there - I notice that in all the speed-runs of the game, this item isn't ever picked up mainly since it's out of the way & serves no major purpose. Maybe it's worth some testing??