Ian,
I would say that drainage, drainage, drainage qualifies. Soils - well, there are too many good courses built on poor soils to make that a true absolute.
I think your question was more at design ideas, like safety, no blind shots, basic green sizes, etc. I would say there are dozens of absolute truths in golf course design, as long as you are willing to suspend the truth in exceptional circumstances. So, maybe they are nearly absolute, or as I call them - Rules of Thumb, often broken.