I am so loving this
The spaceship does reset. You need to keep excavating to find the four pieces of the key - piece number two seems to be a little elusive. There are plenty on nanites to catch in the wastelands - I've found at least one of each variety with the exception of the Polar and the Uber.
As for making money in Oasis Landing, you can have a job in the present and the future. My Sim, who is a self employed gardener in the present, got a wish to join the gardening career while in the future. I looked and it said she was unemployed so I sent her to the city hall where she became self employed there too. Seems that if she harvests things in the future, they go toward her career in the future if she sells them there. If she hangs on to them and sells them in the present, then the proceeds go towards her career in the present. For this reason, it's probably better to have different careers in each time.
You can buy a house (or land and build) in Oasis Landing, so if you wanted to, I can't see any reason why you couldn't just stay there permanently.
I've had one problem though. My Sim married old Ben Kenobi (well his name is really Bennet Obie) who lives in the wastelands, but she did that before she bought a property and I can't get him to move in with her and I can't control him and I can't take him back to the present.
You can't time travel when pregnant, but you can time travel and leave a toddler in the present with just a SimBot! My Sim was pregnant with Bennet's baby and traveled back to the present where she has a SimBot that only has a handy chip. While she was in the present the pregnancy progressed and she couldn't travel again until after the baby was born. I aged the baby up (still just experimenting really) and then sent her to the future on her own deliberately. I expected to get a message that I couldn't leave the toddler home alone, but didn't lol.