I would not agree to extraterrestrials migrating to Earth. Our planet is unreasonably overpopulated, mankind is sinful, destructive, and disease-ridden, not to mention that resources have been exploited exponentially ever since the inception of the Industrial Revolution. You can only dream, though.
You forget something though, if humans get the stretch/warp drive you can bet there would be a mass exodus from Earth to the rest of the Galaxia. Humans were uplifted and abandoned by all the current Sibling races and as such humans would have the right to go anywhere in the Galaxia for having once been their "children".
Humanity my very well be the mortar to bind all the Galaxia races together (I'm pretty sure that's part of the Parents plans since our race could never resist going out and exploring). So if we are out there, you can bet they would want to come to Earth, if only to visit. But plenty would stay simply because our planet has things that remind them of their own homes (ie. the Sahara desert is just like the entire planet of Khemia).
As for all your negativity, well that's your issue. But on the point of resources, once humans can reliably get into space and back we would mine asteriods and other space bodies and get more from them then we would ever get from Earth. Our solar system has millions of floating space bodies that could be mined, not even counting the existing known planets and their moons.
Of course the whole Avia Pox thing would need to be solved first.
Negativity, my issue?😆Sin, destruction, and disease of mankind are REAL! They are everyone's issue! Your soliloquy is cute though, I'll be honest with you.😆Which begs the question: why did the sibling races abandon mankind, I do wonder~? Whatever the case may be, I stand firm on my conviction. I also disagree on the notion that mankind expand into the cosmos because what we do here, we will do elsewhere and everywhere. Satellites having been lost and discarded in space are but the first of many ways in sullying the already perfect universe the Parents created for those being worthy of humanity (do not confuse with mankind). It is not a matter of being negative, it is a matter of being realistic.
There are two worlds based upon your premise - the objective material world and the subjective human world. There is nothing inherently flawed or wrong regarding the world outside the human experience. Consider a rock, branch, and vine. Then comes the monkey who had the grand idea of making a tool with said rock, wood, and vine and going apeshit on a fellow simian because they acquired the mate they wanted. The tool and its natural components are not the issue. Who we are and what we do are consequence of our existence and choices. Remove the human element, the world would be peaceful.