Can we use both rotisseries (the motor on the side and the motor on the back) at the same time?

No, the two BBQ cage skewers in their normal lowest position do not work at the same time as the nine kebab skewers as they clash, but one BBQ cage skewer can be used in the upper position of the side skewer rack at the same time as the nine kebab skewers. On the BarbeSkew II, there is no upper position on the side skewer rack, and so all three methods of cooking (small kebabs, BBQ cage skewers and traditional grill) can only be used independently.