You really have no idea what you are talking about. Some of your ideas go from idiotic to childish.
Also, you wrote;
Essentially, you have to fly the track and profile which says on the plate, but how you do it is entirely up to you.
WRONG yet again. Not all airliners are RNAV approved and therefore must use raw data by law, irrelevant if you are equiped with a IRS and nav display.
If you have done your IR in the UK, you will have noticed that the vast majority of IR instructors (+ examiners) there do not have any actual IFR experience outside their training environment so sometimes you have to take their words with a pinch of salt or two.
IN WHAT WAY? Normally alot of those instructors have done more IFR flying/SPO's in demanding conditions than some airline pilots.
What on earth gives you the experience to question the knowledge of an IR instructor. Please give us your examples of when you had to take advice 'with a pinch of salt'. What type if IR flying were you doing. I guess that you have done some with a UK IR instructor.
You say you fly for fun. Then don't feel you are qaulified to give advice to people on this forum who are learning and trying to get good sound advice. Your previous comments generally show that you do not have the knowledge or attitude to do so.