That was a funny clip, but I'm not too sure about his advise on slipping to get down, sure it is a useful skill to have but side slipping near the ground for most students should be a big no no (unless of course they are flying an aircraft that uses sideslips to control descent) If we teach students to side slip down final all the time then when they start taking paying pax up they will be plastered to the side window.
Yes I think students are flying larger circuits then needed but there is also a point where the circuits can get a little too close, (if you fly AG ignore all of this, it is in no way aimed at you). Turning final at less than 500ft is unnecessary at most airports (there are always exceptions) it invites error and leaves little room for inexperienced pilots. On the other hand turning final at 1000ft is also unnecessary (unless you're trying to demonstrate something to a student) and shows poor airmanship. In a standard light single your final and base speed will be appx. 60-70kts, so to be at 500ft as you roll wings level on final should have you about 1.5nm from touchdown (standard 3deg profile).