Are all of his droppings orange and runny or just some? Are they also what you might call foamy?
Ceacal poos happen every 8 to 10 movements. They are a natural part of a chickens digestion, a sort of flushing of their bowels. They are runny, usually look like chocolate pudding, but can be orange and sometimes foamy. They are completely normal.
Having said that, keep in mind that apples can be a bit laxative and I would cut back on them to a couple times a week.
Now about the sneezing while feeding. Is feeding time the only time you notice the sneezing? If so, I'd say it's nothing to worry about - especially if you are feeding a mash or crumbles. Some birds have a tendency to inhale a bit of the feed into their nostrils while eating. When that happens they do what we humans do when our nostrils get irritated; they sneeze. In the absence of other symptoms such as wheezing, runny eyes or nose, I wouldn't suspect an illness right off.