I see a problem with Drive and Ride as Common skills.
Drive: In the RAW a character from a Primitive culture would have as easy a time using the skill as his twin from a Civilized culture.
Ride: Not every culture has riding animals (native Hawaiians and other Polynesian island nations, Frex).
My fix for this is to make these skills Advanced skills but to put them into the culture packages for any cultures that should have them as a Common skill.
Thus, IMO, problem found and fixed.