You can probably get these on people who have no idea what they're doing, but against any reasonably experienced grappler, even without experience in leglocks, these aren't going to work.
I'm sort of notorious for my massive posts, so I guess I'll just start at the beginning and walk through why they're problematic. I don't know what rating system you want me to use, and there's isn't an objective one anyway, so I figure I'll just walk through my concerns.
Leglock #1: Stepping over into an achilles lock
You are actually walking into a flower sweep. In order of this to work, you're opponent has to put up no resistance, he has to not rotate onto his side (which experienced grapplers start to naturally do when an opponent steps up to turn, from dealing with the basic closed guard passes) and he has to not challenge you for position while you're doing the technique.
Against an opponent who doesn't know how to use his guard, this can probably work, but you're basically relying on him (a) only having a closed guard and (b) not knowing how to respond with that closed guard when an opponent tries to pass.
Leglock #2: Hands-Free Kneebar from the Lockdown
I'm actually not sure that this will work even against inexperienced grapplers. If you have really amazing dexterity in your feet, you can actually grip the achilles tendon with the bridge of your foot and that really enables this move, but even then, the gut reaction that most people have it to pull the heel in towards their butt, especially if they were just in the lockdown,, and that effectively counters this submission.
Also, going for risky stuff like this when you have a really deep lockdown (and the lockdown the instructor gets is really textbook; it's really solid) is a good way to get the guard passed.
Leglock #3: "Toe-Hold" from the Scarf-Hold
I have no idea why an opponent would defend the scarf-hold by sticking their foot in like they were trying to take the back. It seems un-intuitive, but it also seems like a horribly uncomfortable position that you would try and get out of almost immediately, even if you couldn't escape the scarf-hold.
I can see a beginner trying this, but I think basically anyone who's competing has probably worked out that this is not a legitimate escape for the scarf-hold. I don't know why anyone would attempt it more than once.
Leglock #4: Rolling Kneebar from Inside the Guard
This one is actually a classic. People who like to surprise opponents love this technique. I've never understood why. Unless you're Masakazu Imanari and you're going for a leglock to finish the fight anyway, if you get to this position, you should just pass guard, it's way better.
That said, it's a pretty good instruction on the rolling kneebar. I love that he comes in with the heel in his armpit. It's the best way to finish the kneebar. He comes in a little higher when he rolls than I like to (I like to stay really tight to the hips with leglocks, because of experiences with squirmy opponents) but he's a lot taller than I am, so it's understandable.
Leglock #5: Calf-Slicer from Standing
I actually got a little annoyed with this one, because he actually just screws this one up. I'm sure he's a good instructor, and a smart grappler, but if you don't have any thing pinning your opponents hip, you lose the calf-slicer and get your guard passed.
Personally, I take my outside leg and wrap it over the hip, angled so that I can triangle around the knee. I do this move when opponents are trying to pass guard on me all the time (in situations where it's legal, which isn't nearly as often as I'd like) and it has a great success rate off of the back, but you have to apply pressure to the hip, otherwise there's no submission
From the position that he falls back into, his training partner could easily just follow him up and come up in half guard or mount. His training partner actually has to lie flaccid to not follow him up, because the momentum of the topside version from inside that no-gi spider guard actually pulls him that way. This was the worst one of the bunch, which is sad, because it's a great submission.
Leglock #6: The Rolling Toe-Hold from Standing
This is a professional wrestling classic, especially in Japan. It's a cool move. I don't have any complaints about the way he teaches it, except that I've never seen this move work in competition. One of my favorite guys to watch in the world of BJJ was Tyrone Glover, and I've seen him do it in demos before, but I've never seen it work in competition.
It's not impossible, and it's worth going for, especially if you have great leglocks and you're really comfortable in positions where you can easily attack the legs.
Generally, I've got to say I like the message about leglocks. He's right that they intimidate people, and there's basically a moratorium on them in the lower levels of Brazilian Jiu-Jitsu, which I understand but have always resented, personally, as someone who has really taken to leglocks and found them to be a really great tool for learning how to control limbs when you're doing submissions. But his technique is not that great. Unfortunately, there aren't that many guys who teach leglocks who are really great at them.