Re: Atemi waza: good or bad for Aikido?
That is just a safety point. All the atemi waza clearly come from belting uke one in the jaw. Clearly this conflicts with some of the more harmoniouse aspects of Aikido as well as with safety. If you have ever watch Enter The Dragon with Bruce Lee, he used aigamae ate in his first fight -- but he hits instead of placing the hand and throwing.
BTW, anyone who wants to practice atemi in the sense of hitting things, I suggest you learn how to punch from someone who knowns how to do it. Otherwise, you'll likely to break your finger or/and hand... Just a little warning.