Collecting Rain-Water & Sewing
I was pretty surprised that while sunlight was a craftable object, I was apparently unable to collect rainwater in cans and pots. Unless acid rain is a significant issue in the world of NEO Scavenger, I'd expect it to be pretty clean. If not, then it should definitely corrode metal objects it is stored in. This would be a nice indicator of whether it is chemically contaminated, while having the trade-off of also degrading your containers.
It would also be nice to be able to repair fabric objects instead of having them just fall apart. A bit of time spent with a needle and some thread would make things last a bit longer. Most experienced hikers will carry sewing and repair kits to patch holes in tents, bags, and clothing. Some descriptive updates at certain numeric thresholds would also help keep track of the status of your fabric objects before they fall apart completely - perhaps something like "worn", "threadbare", "torn", and "tattered".