The Ramma at the end of siman 612 brings fro the Trumas Hadeshen that there is no issue of muktza for food or drink.
מותר ליגע ביום כיפור באוכלין ומשקין וליתן לקטנים ולא חיישינן שיאכל או ישתה עם יגע
Magen Avraham as brought in Mishna Berurah and Aruch HaShulchan points out that is different than Pesach as brought in shulchan aruch 446:3. There, since a person is eating other food we are afraid he will forget himself and eat the assur food he is touching. On Yom kippur this does not apply. Also on Y.K. the fearfullness of the day is upon him.
The Shulchan Aruch HaRav verbalizes the M.A. differently. He writes in siman 611 that touching food is always allowed. Preparing food, which is naturally more involving is only allowed when preparing it for someone who needs it like a child or a sick person. The only difference would be preparing food for no express purpose which seems trivial and impractical and we might assume the M.B. and A.H. agree. (preparing food for after Yom Kippur is mentioned below)
They all say that if the child can feed himself there is still no reason for the adult to be stringent.
Since touching food leads into discussions of hachana, which is actually the point of siman 611, see there for the discussion. Nowadays we have no leniency and we do not allow preparing food for after Yom Kippur even though this was allowed in talmudic times later in the day.
I didn't see anyone discussing the other items related to the affliction of the day, such as leather shoes. But let's remember that of all the five items, only eating and drinking would have a punishment of kareis. It would be logical to be stricter with those.