Iron is quite common because it is common byproduct of star development. Making iron scarce will mean your planet is lacking inner iron core, which creates magnetic field which prevent radiation to kill life on Earth. So on a planet with no magnetic core, life might not be possible. Or life would have be different (like: underwater only).

So if your intelligent life has to life under water, they would have hard time to get fire! Water surface would be outer edge of their world, and bigger obstacle for expansion than is stratosphere for us.

Iron is quite common because it is common byproduct of star development. Making iron scarce will mean your planet is lacking inner iron core, which creates magnetic field which prevent radiation to kill life on Earth. So on a planet with no magnetic core, life might not be possible. Or life would have be different (like: underwater only).

So if your intelligent life has to life under water, they would have hard time to get fire! Water surface would be outer edge of their world, and bigger obstacle for expansion than is stratosphere for us.