chicken strips in honey-mustars sauce

I am looking for gluten free recipes for my grandson, who is temporarily living with us. This recipe looks really great and it is the type of thing he would like. Two questions. 1. Can the flour be replaced with potatoe starch or cornflour (or even rice flour)? 2. Can it be reheated in a microwave, as he takes it to school with him? Thank you and Shavuah Tov, Esther Leah