Ok, I just pooped out a Koro air speeder to run around a planet while I wait for building stuff to happen. Now, the question is when I fly up to the atmosphere, can I then fly across Lava and caves? I'm guessing yes... I just don't want to fly across a lava field up in the atmosphere then suddenly die for some stupid reason.
I could even stand on ocean terrain when I exit my ship (restricted terrain for Trandoshans). All NPC builders that have finished can apparently walk on water as well.