OK in order hopefully.....
The TK 30hrs is something the CAA are trying to 'recommend' with no legal grounding. I discussed this at a recent audit and told them that we would be sticking with 10hrs until such time as it was proven ineffective. They accepted this.
You are incorrect on the MEL, it only applies if you put it in the manual. It does not have to be in the manual. If you don't like it don't use that bit. The manuals are a guide not the law...
Exam invigilators. There has always been a requirement for the exam to be invigilated!! This does not mean someone sat in the room with the student, it could be the GRE in the next room, the receptionist or an FI ensuring that the student does not cheat. This means ensuring that they only enter the exam room with the required materials for the paper and nothing else in the room that might be used to cheat.
The requirement is for the GRE to issue and collect/mark the paper so its actually no change from the old system.