Tom;
I think MacKenzie would agree with me on the first point. He must have wished his list had been '12 essential features' - that the first statement had never been made.
It is an advantage (for many reasons) to have two loops of nine but not essential. I particularly like Woking GC where you return after 14 holes, before the finale.
With reference to the second point (his fourth) I think he might disagree with me, he writes in length about the necessity of undulating greens and fairways. He does, however, emphasise the naturalness which these undulations should take (see point seven, ranked 2). If he were alive today he would perhaps recognise, unfortunatley, how these undulations would be difficult to maintain and to play upon especially with today's cut heights.
When I ask people about the greens on their home course most, sadly, give me an answer in either speed or condition. The need for speed has corrupted many of the greens on some of the finest British courses. Undulating fairways on the other hand are nice but not essential.
On his second point he writes,
'I usually like to have four one-shot holes, two in each half, but....we should be influenced primarily by the nature of the ground.'
He was a great beleiver in golfers of all abilities being able to enjoy the game. One shotters and drive-pitch holes do provide more enjoyment for a wider scope of players, everybody has a bite at the cherry, if you like.
He was very flexible on this point though. The reason for his comment I think was that The Doctor, who had more inclination for variety than balance, wanted to down play the need for pre-determined distances, sequences, hole lengths, championship course length etc.... He did this, ironically, by trying to pre-determine the number of par x holes.
If a course allows for four or five par threes and a few short par fours then great, but if not, so what. It's not essential.
What is important is that none of these statements are exclusive to one another. They are all interwined with one another in some way and it is how well and wisley each part is used as to the greatness of the finished article.