Ok first thing I'll address is you question about how to make the Sniper Pistol and Rapid Fire Pistol. You can see the rough stats for the Sniper Pistol in Notrium's FAQ thread, along with another new weapon I added. To make Sniper Pistol you add a Long Metal Rod. Yep its just that easy, but you'll need to make special bullets for it as well so make sure you not only have bullets, but ehter as well. To make the Rapid Fire Pistol you need to make a cooling unit for it, by combining a glass tube with an ice pack, than combining the cooling unit with a normal Pistol.
Secondly I must pinch you, there is reason I put a battery at the start area, that's to help you out as the Android before you start losing energy, so don't use it right away. If you didn't pick it up, make sure from now on you get EVERYTHING at the start area before you explore, I usually find a couple healing plants there on almost every game.
The Android is supposed to be hard to start with by the way because it can surpass everything else in longevity, since the human and alien can't upgrade their food, the Android is the only race that can upgrade their food source. Make sure every chance you get you make a Battery Extension because not only does it add 30 max, it actually gives you 30 energy as well.
About not being able to pick up things, which means they're probably on the boundary of the map, switch the graphics mode to 1024 x 768 32 bit fullscreen and you should not have the problem anymore, nor should you get that annoying bar on the side of the screen which seems to trail graphics. I think both problems are going to be fixed in the update since they are to do with Notrium and not the Expansion, so I have no control over them.
I can't really say why you would see any of the plants on your radar, but I suppose I'll check and see if somehow I accidently changed them to be detected..