I was a student at Skymates. Was training with them back in January this year. Its a very professional and friendly place and their airplanes are very well maintained. No problems with the instructors or admin staff over there. The only "complaint" i would have is that public transport is non-exsistant so a car is necessary. Cost of living in the area isn't too bad either.
If your instructor is doing aerobatics in a non certified airplane, i would think you as a student should voice out something. As a trainee pilot, we should learn to take control of the situation if things are going wrong rather than let circumstances take you where you don't want to go.