MJ,
I would agree with your comment, and admit it would be the ideal situation. It is interesting that quite often having 4 training aircraft in a circuit can create the extended downwinds etc which seen so common.
I recall from an FI seminar some years ago, the speaker suggesting it should be taught that if you cannot turn base at the correct position then you should initiate a go around from downwind and re establish in the circuit. If I recall the speaker explained he taught go arounds from every part of the circuit and regarded a landing as a bonus!
With regard to calling long finals at 4 miles, I seem to remember that any flight more than 3 miles from an airfield was categorised as a cross country, so are we now calling final whilst still on the nav leg?
Interesting thread though.