Question 1: p_queen + p_rook = 1.

This is because a queen-traversable path exists from the bottom row to the top row iff a rook-traversable path does NOT exist from the left column to the right column.

Question 2: p_bondsman = 1/2.

By symmetry, p_bondsman = p_antibondsman. Also, a bondsman-traversable path exists from the bottom row to the top row iff an antibondsman-traversable path does NOT exist from the left column to the right column.