I've seen some punching and kicking in Aikido demonstrations but punching and kicking weren't part of Aikido (as I was taught it). Any punching and kicking that was taught was purely from the point of view of giving uke a few more arrows in his quiver. Kicking and punching were used in my old classes public demonstrations where uke would punch/kick tori. Tori never punched or kicked, they only reacted to those attacks from the uke.
Here's an example of what I refer to. Uke attacks with kicks and Tori (Christian Tissier) responds:
"Let your food be your medicine, and your medicine be your food"