Can the traditional grill on the large Charcoal/Gas be used at the same time as the kebab skewers / BBQ cage skewers?

Yes you can with the two larger models (Charcoal & Gas), as they come with a half grill. However you can’t with the BarbeSkew II as it comes with a full sized grill. But you can purchase a half grill for it separately online. See accessories page.