2. 99% (or 90% or 70%, depending on the quote) of Aikido, according to Ueshiba Kaiso.
According to Shioda in his book, Aikido Shugyo:
Many of you are likely surprised at how often I use atemi. This is only natural since when we talk about Aikido, everyone is caught up in images of wrist grasps and flashy throws. However, Ueshiba Morihei Sensei himself, who was my master at one point, expressed himself in the following manner. He said, "In a real fight, Aikido is 70 percent atemi and 30 percent throwing." Based on my own experience, I can say that this is precisely the case.
It's been said that Shioda's aikido, of all the students, was most like Ueshiba's. It has also been said that Ueshiba was the favored student of Sokaku Takeda. However you want to look at it, the focus of the quote is "real fight", not training and not in the dojo. It seems that when this quote/percentages are used, everyone forgets that part. Should you still not be convinced, look at the films of Ueshiba, post-war, and count the number of atemi he uses. He doesn't connect and sometimes doesn't come close, but they are there.
In Kisshomaru's aikido, aka Modern Aikido, atemi has a much, much smaller role. Does your practice use atemi as Ueshiba did, even in his post-war years? Why not?