Crab,
1/ I am not an FI on helicopters but I have a lot of experience of ab initio flying training, and a fair bit of instructor training and testing.
2/ I never said a TRI ticket was equivalent to an FI course pass. You are making it up.
I'll agree that the amount of basic instructional technique on a TRI course is pretty minimal - fortunately I had my instructional background to fall back on.
3/ You have 4000 hours of something. So what? I know folk with 15,000hrs who were not very good pilots. Perhaps you have 4000 hrs of doing it very badly - who knows?
4/ Your comprehension of written language seems limited. I said that when practising a manoeuvre one should try to maximise the number of times it was carried out correctly. That is not the same thing that you imply - that it should be perfect first time. Obviously that is unlikely to be the case. My point is that it is the instructor's job to help the student get it right. Presenting the student with an exercise you don't know if he can do and which in fact he doesn't know how to do, is unhelpful for any purpose other than crushing him.
5/ Yes unannounced checking of ability to perform an excercise is part of preparation for testing, but only in a controlled environment where you are familiar with the student's status. Randomly carrying it out on a PPL who is struggling is not helpful.