I think it's both fun and instructive to compare the whole of human civilization with an individual human in terms of lifetime and maturity.
Interesting, I never thought of advanced aliens as looking out for us like a mommy/daddy figure as you imply. I've viewed them as just that, advanced beings keeping tabs on us either for their own protection or to assist us in ushering in more advanced eras of our own....Aliens are great for science fiction, but as scientifically minded person who rejects religious creationism and the need for a god or gods, I view the preoccupation some people have with the idea of super-intelligent aliens "watching over us" (for whatever imagined purpose) to be a surrogate replacement for a deity.
I have a great fascination and interest in scientific research into interstellar travel. So far our greatest minds have failed to find good reason to believe that faster than light travel is ever likely to be possible. The only sound theoretical idea is the Alcubierre drive (which is the Star Trekian warp drive and Alcubierre acknowledged as his inspiration for his theory). However that remains a pipe-dream, due to a large number of theoretical stumbling blocks ... not least the improbable energy requirements. Even so NASA has been operating a warp-field detector so we may yet detect a passing Vulcan starship ... and let's hope it ain't the Klingons ... or the Ferengi.
On the other hand the technology for sub-light travel is entirely feasible...
... along with District 9. BTW, if you liked the Alien Nation TV series, be sure to check out the original movie that the series was based on.There was a TV show called "ALIEN NATION" which showed what MIGHT happen if ETs came here. They were the new people to be DISCRIMINATED AGAINST!
Maybe we could get lucky and the aliens have a major need for carbon monoxide.I think the least-intrusive would be alien traders offering to buy some resources ('People of Earth! We Want Your Ammonia!') and negotiating a deal. 'Yeah, the saucers are all up in Canada working the zinc mines, no biggee.'