Nice doublepost there, GWG. Missed the Modify button?
If you'll note, the posts were identical.
I'm going by the original X-Com implication that unlike alien alloys, Elerium is impossible to replicate.
Which requires there to be some reason why this is so. Personally, I'd prefer it to be available for a few reasons:
1. It makes the XCOM project's influence on the world that much more obvious, making the player's actions in the previous game that much more clear.
2. If elerium is common, or at least available, it explains why XCOM doesn't have its vast reserves of elerium, plasma weapons, and such any more: They were cleaned out because if they ever needed them again, they could just buy some more from 115 Inc and Ares Arms.
3. You're not likely to be getting elerium from the deep horrors. Hence, you won't be able to get new titan armor or anything.
4. It's kind of pathetic if the XCOM at the beginning of the new game is so incredibly weaker than it was at the end of the old.
Plasma would not be used because by the time the terror missions happen, you would not have it.
Wait, isn't this a sequel to XCOM? Even if no new elerium and such can be made/found, what happened to the plasma weapons used in the first game?
Even farther into the future, it is not going to cost any less to make, so it's not going to be an ubiquitous weapon...
Why wouldn't it cost less? Plasma weaponry used in the first XCOM game would logically be the prototypes and whatnot, with plenty of room to expand and improve. And while it wouldn't be ubiquitous, you'd think they'd save some for the special forces team meant to fight off future alien invasions...
and since you would have been fighting on the seafloor, portable railguns scaled down from the MEC weapons using the Plasma-related technologies make more sense as the "standard" infantry weapon.
Why should we hinder our land operations, then? Especially since they're arguably more important?
Your opening is untouched by this premise, btw. The meteor swarm happens as a cutscene after the initial mission, maybe literally cutting to the scene of the meteor striking the ocean immediately after the result of the Ethereal's interrogation/confession/warning is made known to the player.
Ah. Neat.