1. Nearly all Ground Vehicles can move across GG terrain.
Is this a rule typo, or intentionally done this way?
2. There are some fast Speeders which can enter caves, while most Speeders and Ground Vehicles can not. (V-Wing Airspeeder for example)
Is this a rule typo, or intentionally done this way?
Basically yes, two ground vehicles rather similar to others can't cross GG terrain while all others can and most vehicles capable of going into cave terrain are either slow or an emergency vehicle, and then the V-wing which is very fast.