I've watch that a few times, quit a wile ago >1yr. It's a interesting idea, although I disagree with his solution.
And he is incorrect at about 4:30 where he says that you can't see a laser beam in broad daylight, or lighted areas, We all know you could see a laser in light areas as long as the laser is very bright, like 100W @ 532nm or similar.
There are just too many requirements to make a lighsaber that are not possible to do at the same time. And then there is the "minor" problem that any laser powerful enough to cut through anything of significances wouldn't exactly be eye safe.