Personally, I like some of your suggestions! I really like the idea of specific scientists asking for specific types of signals and building relationships with them. But I'll say this:
listening to some signals could cause special events to happen
I'm pretty sure this is already in the game! There's around ten signals that just acquiring them will cause an event to happen, and I think there's at least one signal (a drive you find somewhere in the world) where listening to it causes an event.