It appears by the picture that two screws have been placed into pilot holes that are drilled into the luft track at the base of the mast.
Nope, no holes drilled in the mast. Use square nuts that slide down insde the track (they're square so they don't spin when you tighten the screw).
The screws should be No. 10 stainless steel machine screws. The combined shear strength of the screws would be over 1000lbs, so the risk of breaking the screws is pretty minimal. You also want to place a drop of loctite on the screw so they don't loosen up.