gerry456 wrote: 2. He shall pass the four tests called the Powers of the Sphinx.
Is this a specific spiritual ordeal that is induced by setting out upon the path? If so, in what ways does it manifest in people?
Crowley gave specific (unpublished) instructions in how the Neophyte is to be tested.
But to answer more generally: This is a task that never ends. As I gave (I think it was in a long footnote) in M&MAA, the test becomes deeper and then subtler as one progresses. The key is that the four should be developed equally, as if they were the four sides of the foundation of a pyramid - build unevenly, and the structure eventually collapses on itself. In this sense, the test never ends; but, for the Neophyte level, in establishing that foundation, there are four specific tests passed to those responsible for testing Neophytes.
Also on the Neophyte; He shall in every way fortify his body according to the advice of his Zelator, for that the ordeal of advancement is no light one I presume that this bodily fortification is maintain a flexible spine and doing stretching exercises so as to equilibrate the painful impacts that asana work has on the body?
It's everything. Multiple levels. And I think it showed great wisdom not to lock this into a particular instruction (which would have become rapidly dated) but, rather, to leave it up to the particular instructor of a particular Neophyte to give counsel suitable to that person. In general, the body has to be able, strong, capable of enduring significant shifts in energy, and all sorts of other things. Be basically healthy! (Your one suggestion is way to narrow.)