On your second question, it would depend on if the moon is in the solar system's ecliptic or not. If it isn't, then dark periods when it is behind the planet would be very rare, like say once every 22nd orbit or something. The darkness would also only be like 1-5 hours, depending on how far away the moon is from the planet and how large the planet is.
If it's not tidally locked there will be four light periods, one is the star with pretty high brightness, one is the star and planet which is really bright, there is the planet which depending on how close the moon is could be anywhere from indoor lighting to only a bit brighter than the moon, and no illuminating bodies (like a new moon night). Although the amount of different light periods increases with the amount of moons, but this is assuming there is only this habitable moon.