Is a single line for each point the best, or can one line be routed through all and secured at the ends?
To answer your question re: separate lines or a single line for all reef points, I believe this depends upon the size of your main. Years ago, I sailed on smaller boats which employed a single line that had to be threaded through each reef point - such as in this illustration:
This was time consuming - with the use of a separate light weight line at each grommet being much easier. Simply tie a knot at each end to keep the lines from falling out.
My current boat has hooks like Valiente's and a single line at the clew end led through sheaves inside the boom, and down to the mast base. I don't use any lines at the reef points, since when the main is reefed, the lazy jacks hold the excess sail against the boom.