Does damage reduce a unit's might value, and can a unit with 6 might that has taken 5 damage be targeted by Gust (which targets units with 5 or less might)?

Ruling: No, damage does not reduce might. Damage and might are separate values.

Nuances:

• Units are killed when they have damage greater than or equal to their might (and the damage is non-zero)
• A unit with 6 might that has taken 5 damage still has 6 might and cannot be targeted by effects that require 5 or less might