^ Yes.
I was trying to go a bit further than the biological, chemical and physical--apart from the fact that those things are our social creations--limits. They very much exist yes, but, I was speaking of the problem of choice, individually, and socially, the problem of communication. Biological, chemical and physical limits do not determined the whole, they produce the theater in which a lot of different things may happen.
This human charade, as a species, may well just be suited for mass suicide. My personal cut is that it is, in the land of the late historical experience of imperialism, often called capitalism and progress.
It is a question whether we will make it out of this one. In regards to this, anything can happen because we play a board in which its conditions are not entirely determined--there is, as you adequately put, space-time considerations to be taken into account. It's a bet, the value of what we risk, determined IMO in what decisions are we to produce in our existence as social beings.
And the current social arrangement is of human crops, automatons, and the empire.
...Remember this is my severely distorted view.