4 - They can only fly fighters, much the shame
Actually, if you go out in the fighter, they will take control of the mothership and fight to their ability. My NPC pilot is almost at the same level as me but she flys FA-off much better than me, except when doing ground flying, for some reason she crashes into the ground if I'm flying low in the fighter. I believe the problem is they are programed to fly in wing formation whenever not engaged in combat.... to avoid this, either tell them to hold position if you just doing a little canyon running, or the alternative is to not take the npc pilot if you plan to travel further than 25K (that's the furthest a SLF is allowed to travel away from the mothership..... But without NPC, mothership will fly in auto-pilot and maintain an elevation of at least 1.5K above planet surface, but will also stay about 2K away from you and not attempt any wing-formations.
My big complaint is that I have 2 NPC pilots... 2 SLF's, 3 copilot seats... but can only use 1 at a time. Makes no sense, and I can't fire the second pilot cause they're sisters. So the older sister ended up just being a free-loader, collecting on the money me and her lil sister make.