Paras take over for me all the time. They know the students and their routines. It's kinda frustrating at first, but I understand, especially if they are full-time (subparas I would be all eh about, unless I know and work with them and we agree to work together). Paras I feel are a huge help, especially for subs, and ESPECIALLY if I teach a special ed class.
Also, I use stickers for token economies instead of candy, just incase. I have always been too scared to give out candy.