Not sure what the regulations are in the UK, but in some countries, certain maneuvers such as spins are no longer required and actively discouraged. I personally think knowing how to get into trouble, and how to get out of it, should be a basic skill all pilots should have. Kind of like learning to slide a car.
The other thing that comes to mind is find out how they charge pre- and post- flight briefings. In the little flying club I was at, we'd sit and chat before and after each flight over a cuppa. Technically, there's a fee but I never had to pay. A few of the more professional flying schools around here would happily start a timer and bill you for it though.