That's non-controversial, regular knowledge right? That the proto iron age happened all over in 1 or 2 centuries in which meteors dropped iron from the sky. It was in regular history books when i was a kid.
They always brush right over why it was raining iron. Isn't that crazy wth is that about?
The core part is, as far as we know, due to the pressure exherted by the weight of literally the whole world resting above it that keeps it all held together. Can't answer for the magnetism part.
That makes no sense. The core just went from molten to highly compressed gas. On the other hand we have all the actual heavy elements,...2x, 3x, even 4x as heavy all over the surface.
To be honest, I'm also confused as to why they say the core is made of iron and nickel, when lead,gold or uranium are far denser.
The whole planetary evolution is bunk like the BB it's tied to. You aren't supposed to know layers are added at regular intervals. Look at the half-lives of un-stable elements (those with half-lives). Don't exactly jive with a 4 billion year old planet does it.