But you are putting humans in 1 pot when that is not how the world works. In reality corporations in major economic and highly advanced nations would create completely sustainable systems as soon as the price for resources exceeds that of 100% recycling, which would give these corporations massive advantages on the global market. Corporations will push to make recycling mandatory even in countries where the government has been braindead or run by idiots once that happens.... This is one of the very few things where the free market will indeed benefit us. In essence, the coming oil scarcity (which is imo the only important upcoming shortage) will cause massive disruptions yes. But some nations will prevail. China, Germany, Japan (most likely).... basically all the nations that have enough economy power and sustainable energy sources to weather all the effects and disasters...
But to your numbers ,p
Actually it is unproven that any developed life would go through radio wave based communications. We are just assuming it because we haven't met any other life. Do you see bacteria building radar dishes? Yet clearly they communicate on a basic level. Not every species has to have our biological inadequacies when it comes to communication methods.
A good example is sea borne life, or any other life that has evolutionary traits different from ours making long range communication a biological given trait, not something they need technology to do.
At least as far as we know.. yeah
As you say, it was dumb luck we as inadequate as we are came to be the dominant species with the furthest technological development so far. But it does not mean every other species would develop identically. I think Inter-Stellar travel would be an absurd waste of resources until all available colonization targets are full or exploited. A species could theoretically spend 5000 years perfecting terraforming every planet and moon in it's solar system and build a dyson sphere before it would ever properly explore deep space exploration. And at that point, I think it's more likely they would have jump gates of some description, meaning they would travel on fixed paths and only explore "locally"
The expansion right after the "big bang" was FTL. The universe is proof FTL is possible. Whether it can be used to travel to specific locations.. well who knows. But it can't be impossible. But yes, it would not involve a thruster and a straight line to the target. But who is to say that's all there is in our universe.
I think it'd be more likely a REALLY advanced species would build world ships and not travel willy-nilly through space.
And that's even assuming they build ships, as opposed to BEING the ships. Or growing them.
My point being, the Fermi Paradox is too close-minded. There is no proof species would develop even REMOTELY like we do on planets with different conditions. So any assumption based on OUR development is flawed.
But to come to a conclusion. I think oil depletion and climate change are chances for humanity to push forward. Many nations will fall, and billions will die. But technology will make some nations become strong enough to survive and prosper. But that's my technocrat mindset speaking. I could be wrong
But hey, It won't bother me. I barely make it to the oil depletion the way I live.. and I don't mind. I had a blast so far, and a 50m higher sea levels wouldn't even bother me. I live 130m above sea level (and away from any river) ;p