I mean, it's a game about space stuff and we've mostly been fighting grunts, wild creatures, and pirates so far. It really wouldn't be that hard to implement characters like royal guards or assassins that possess far more advanced armor, weapons, and shields as our role in the universe grows. The enemies we fight don't have to gain new powers (although they certainly could if it fits them), all they need is better gear to simultaneously provide a greater threat to us and also give us more incentive to fight them in order to gain that loot for ourselves.
Also, yes, please give us an upgrade system for our weapons. It's probably not going to happen, especially not anytime soon, but I've said before that it would really help allow us to use the weapons we feel are thematically fitting for our characters instead of just picking from the three or so weapons from each category that dwarf the power of everything else while also giving us a reason to return to different areas of the game that might have otherwise been forgotten in order to get the materials needed for the upgrades.
As for money, that's just a number. There are basically infinite ways to naturally implement that into the game and I'm not too worried about it.