Re: Turn onto xwind and final at 500' - why 500'?
The trouble is that if it isn't law, three things will happen.
1) You will never know what the guy in front of you in the circuit is going to do.
2) There will be more accidents caused by people emulating James Bond on takeoff.
3) There will be more accidents caused by unstabilised approaches.
As the saying goes, "rules are for the obedience of fools and the guidance of wise men" or whatever. As a student and as a low time pilot, I appreciate the existence of the rules because it helps reduce uncertainties - both in terms of expectations of what others are going to do, and what I myself am going to try and do, in other words, mental discipline.
For an idiot like me, starting a climbing turn at say 250 feet, while cycling gear up, setting climb MP, RPM, fuel pump off and engine instruments scan is asking for trouble. The 500 foot stipulation gives me TIME to get things done in an orderly manner - and then start the turn.
Same on final. I like the time to sort things out and make a mental decision about the stability of my approach. My decision to land is at 300 feet with a PUF check, carb heat off (if fitted), or go around.
I've done a few glide approaches where I've still been turning final at 100 feet or less, but that is under instruction.