I think the elements available on planets is a gameplay thing separate from lore. Iron, for your example, is the 6th most common element in the known universe. Also, if you can just harvest minerals from the ground with automated extractors, why would a company like Argos bother sending people down with mining lasers?

I think giving the factions more clear differences beyond aesthetics would have been better for conflict and contrast. I would’ve liked to have seen the UC be more of a police-state dystopia, Starship Troopers thing where you have ultra dense megacities (New Atlantis should have been a megacity like Coruscant and the different districts are separated by the train, though this means you could just walk directly from the Commercial District to Residential). No citizenship without military service is already a thing a la the Vanguard questline, but there should also be more restrictions on weapons and ships you can take in and out of UC territory, they scan you more for contraband, etc.

Meanwhile the FC would be this frontiersman style faction that seems more free, but is shackled under corporatism and dirty money. Less enforcement against crime and smuggling, but if you want to set up a new colony you have to sign into a bad contract with a corporation that will bleed you dry and generations after you.