A lot of the problem at Kidlington is that the circuit is v. tightly constrained, by the danger area at Weston-on-the-Green to the north and by the Brize CTR to the south. There's therefore v. little room to extend downwind for spacing, hence lots of go-arounds happen due to a/c getting too close to each other.
They also encourage traffic to join the circuit from all sorts of random directions ('more commercial'!) which is a recipe for disaster in such a busy and constrained pattern.
A parallel runway would help, but (a) I doubt that there's room on the airfield, (b) it would b***er up the helicopter training, and (c) the Duke of Whatever in Blenheim Palace would just ~love~ traffic in the opposite circuit flying straight over his back yard!
Well done to the instructors for keeping themselves and the students alive!