The analyses of a text

The protagonist is one of royal family members of Amber.
He made a date with a daughter of the prime minister from a neighboring country Begma.
And he went out with her, showing her the town when she wanted to go a big stairway going up the face of Kolvir which the palace sat on.
They at last arrived the top of stairway, and are now climbing down it.

The landings where the stairway switched back were haphazard affairs, hacked wherever the contours of the rock permitted such a turning. Consequently, some descending stretches were longer than others and our route wandered all over the face of the mountain. The winds were much stronger now than they were above, and we found ourselves staying as close to the mountain's side its contours permitted. Had there been no wind, we probably would have done the same. The absence of any sort of guard railing made us shy back from the edge. There were places where the mountain's wall overhung us for a cavelike effect; other places, we followed a bellying of the rock and felt very exposed.
["Sign of Chaos" of The Great Book of Amber by Roger Zelazny]
I'd like to know if "hacked" modifies "the stairway."
I'd like to know if "had there been no wind" means "even if there had been no wind.": a concessive, conditional clause
And I'd like to know what "for a cavelike effect" means.
Thank you in advance for your help.