There's some special weapon made with meteor metal?

They exist as a ritual weapon, because it's kind of a sacred material, but it's not very strong to do weapons, I doubt anyone will find it a lethal use.

Imagine that you catch Rago and your sister, let's say... playing doctors... what will be your reaction?

Ah... Reika... This...

You can train/rise/modify monsters to control them?

As you have seen in this chapter, there's trained creatures and creatures that influence others.