While I certainly don't claim to be an expert, my mother make a few dozen types of cookies (biscuits) with devices similar in design. Most use the same recipe, but may use different coloring and/or flavoring. I'm sure many more recipes can be used, but as far as chips, or chunks of anything else, depending on what design disk you're using there is a good chance of it clogging, or just straining the bits out. Usually my mother will make the cookies, and decorate or add stuff after.
She makes wonderful little candy bar cookies by making a line of dough with the 'zigzaggy line' disc, places an assortment of Hershey's miniature candy bars on it, and cranks out another line on top. She then cuts them apart and seals each using a fork dumpling style. I'm sure you could do the same with fruit, and other whatnots.
Also, some recipes don't hold the shape as well. The chocolate chip cookies I make would never hold most of the shapes even if I could get them through the gun.