The second part of this two-piece paper applies the method developed in part 1 to show some interesting features for the practical analysis and design of leaky-wave antennas. Novel analytical formulas based on the propagation and radiation discrete Parallel-Plate Waveguide (PPW) spectrum coefficients described in the first part are presented, in order to calculate some interesting propagation and radiation aspects of leaky-wave modes. These formulas will be used in the design of a slot-line millimeter-wave band leaky-wave antenna, measuring parameters such as reflection and radiation losses, polarization purity, and coupling with undesired channel-guide leaky modes. Comparisons with previous works for slot-line leaky-wave modes are presented, together with novel and interesting results, showing the usefulness of the proposed approach for the design of practical leaky-wave laterally shielded planar printed antennas.