Making cartoon... do I stay in Character Animator?

I am making a cartoon for a 1st grade class based on a book they read.  Each student drew their character and recorded their lines.  They also drew backgrounds. 

I am fairly inexperienced in both Character Animator Pro 2025 and After Effects which I haven't used in many years. I am wondering which application I should use for the main timelines. I can see how I could do it incharacter animator but I have a few characters that will not animate in a traditional fashion. For example there is a stapler which will move a giant mouth (being the base) up and down. Can someone give me a workflow of how I can use character animator to do the major characters and also do other animations such as the stapler?

Also, I am trying to use some of the premade characters to steal their eyes and mouth.   When I bring them into Photoshop I can see all of the hierarchy of body parts. Elite sum and add my own as you can see in the attached picture. When I bring them back into character animator  none of the triggers remain. For example, I would like to be able to switch between a mouth and an alt mouth but it won't let me. Any assistance would be very appreciated.