Note that they only have to be friendly to themselves to survive to get into space. What if the mechanisms that ensure their peaceful cooperation just don't apply to naked apes? Just one example: we say that a smile is "universal" but that's just because it's wired into our species. An alien species would've been subject to an entirely different evolutionary context. A smile would be meaningless to them. We still don't know everything about how altruism works in our own species. I posit that we have not a clue about how it would work with aliens, or even if it would exist at all towards us.

(Another example: when was the last time you felt pity or forbearance in response to a reptilian submission signal?)

I have no idea what a low albedo impactor is

It's a kinetic projectile that doesn't reflect a lot of light.