Regardless of whether it flies or not, we do need some form of recon. Could we create a radar system with the materials we salvaged from the crashed ship?
The CAD system has blueprints for a great deal of machinery, and Sensory Arrays are included in this.
As a note, the system It doesn't have a "giant comprehensive list of every device We have invented ever in the history of us", but it does have the basics needed to industrialize, create biolab equipment, and a small handful of useful devices. If the computer goes down or is lost, most if not all of the possible tech is lost. So, You
really don't want to lose or damage it, because it would lead to being absolutely fucked.
If we post sentries, we will be noticed. We got no camouflaged units, nor any coldadapted ones. And we haven't got the royal jelly to make them.
And does it matter if they come and go? They won't find anything, after all.
Edit: Them finding us is a very significant event. There are species out there that would scorch the planet blow up the sun just to get rid of us.
Minor edit there. It's a full-out Class X-2
Apocalypse scenario.
Really though, the atmosphere itself is the best source of carbon we have. Perhaps grubs could be specialized to consume soil, inhale atmosphere, and secrete steel (and slag) after receiving sufficient nutrition. Maybe even a new specialist builder drone idea, once we have more Royal Jelly.
The Nurse slowly processes elements that it consumes and breathes, as do the Grubs. Obviously, two Grubs and 1 Nurse can't replenish the Universal Elemental Stocks faster than we can use them.
As an additional note, I'd like to point out that our element/resource supplies are as follows:
Water
Titanium
Gold
Copper
Superalloys
Universal Elemental Supply (Hydrogen, Helium, Oxygen, Neon, Iron, Nitrogen, Silicon, Magnesium, Sulfur)
Iron Spheres
Large Iron Spheres
Scrap Metal
Scrap Plastic
I can't tell you exactly how much because it's not that hard of sci-fi, but I can tell you that as it stands, we have more than enough to establish an industrial base and equip our tiny little army. Once the eggs get going, the supplies will run out quickly.
EDIT: I go to see the girlfriend today and this weekend. Updates will continue, but slowly.