
Visible crew/equipment: In the fourth part, as the mortally wounded fighter is falling against the back wheel of the cart, the camera is positioned low and its shot is panned upwards, revealing the top of the cyclorama, a large concave backcloth that has been pulled around the studio walls (presumably BBC Studio 1) to give the impression of daylight in these studio-shot but supposedly external scenes.
Answer: TARDISes are generally available for properly authorised use on Gallifrey; they're not usually assigned to a particular Timelord on a long-term basis. The Doctor stole his when he left his homeworld.
Tailkinker ★