Re: Beginners should not be allowed to act as uke.
I am not a very generous uke, and I discourage my practice partners from giving me any easy flops. Sometimes they get mad, but if their waza's weak they need to find out in the dojo.
Some Aikido schools should definitely NOT be offering instruction in self defense. If they are, they need to teach techniques that the average 6th kyu student can use on anyone, not just someone who knows how to yield properly. Like Hiji Shime, Kote Gaeshi, Ude Garami and (of course) Irimi Nage.