I think the sensor only works for the battle screen and
scanning a planet. You need the ship detection system or
the improved version to find ships. They cost 1500 and 3000
respectively and are in the sensor category of ship upgrades.
Sorry, but you are wrong in several ways.
1. I've noticed late game a lv 5 sensor will detect a lot more ships, and farther out at that too, than lower lvs.
2. Scanners "scan" farther the higher their lv, I know this from the nav computer and how it lays out blue dots.
3. The LR fighter starts off with a ship detection system, and I've seen maybe one ship on my screen, once, I think.
...and Neo, that doesn't really sound like a fun planet. And you would get murdered, rather quickly.
Possible bug: You can throw as many grenades as your heart pleases in one "turn", therefore you can kill anything, with enough grenades. That might be intended, but meh.
Something overlooked: If you find a friendly creature, you can talk to them for pretty much hours and get random art items for free, which you can then sell for big bucks. Perhaps after a while the animal says "leave me alone", and if you don't it attacks?
Also, I can't find a use for rovers. They don't work when you are off planet(maybe a bug), and can be destroyed by aliens which makes them a pretty heavy investment to just wait around your ship while your rover explores.