I believe it is the devs intent to have multiple forms of both asexual and sexual reproduction, but, for efficiency reasons, I’m guessing most creatures will likely end up evolving to either lay/implant eggs or have live births.
I certainly hope so, I guess we will see.
There will likely be stages of growth, as part of the Caste System, though the specific are still very much up for debate/design.
There are multiple discussions about the possibility of including competing for a mate and/or mating rituals.
The main problem with this, Iron eating becomes less efficient when oxygen is present. In an anoxygenic environment, iron eating would likely be the most efficient way to survive. In a world filled with oxygen, not sure how well it can sustain you. Though you can bet I will try to make one work anyway.