Re: How many instructors teach Ukemi Waza?
I've always thought that Aikido doesn't get really, REALLY interesting until you can breakfall fairly well. There's nothing quite as fun as getting slammed really hard by one of the top instructors and traveling 3 or 4 meters in the blink of an eye and being able to get up after that. Usually with a huge grin and a "do that again" feeling painted all over your kamae.
It's also a relief to trust in your partner enough to know that they can do a breakfall from whatever you can throw at them...and vice versa.
We teach many breakfalls in our dojo from day one. We usually don't start teaching flips until after the first or second test, but that, too, depends on what's being taught during the class and whether the student wants to give it a shot or not. Like everything else in Yoshinkan, there are very strict standards in the various breakfalls that we teach as "basic" especially in the beginning stages.
Another point is that I feel that you probably learn more as the person receiving the technique than you do actually practicing the throws. So, if you can breakfall without worrying about it and "feel" where you are being moved without resisting that direction then you can probably get more out of the whole experience. After all, since it takes 2 people to make a single technique, there's not much good at only being taught half of the technique.