We vs "cool" aliens:
We/humanity, is, at this point in time, primitive - we've been serious about technology for only ~400 years.
Civilizations that can build ships able to travel to near light-speed developed technologically for tens of thousand of years (most likely).
You are saying that WE can't build near-lightspeed ships, WE can't "see" planets in detail (we're getting closer to this goal, though), WE can't avoid a space rock (which is actually not true when we're talking "rocks"), etc.
You're saying nothing about a species thousands of years more advanced than us. If something can be done according to physical laws, then this species should be able to do it.
WE are, of course, nowhere near the level of technology needed to build a near-lightspeed ship.
But we're relatively close (a few centuries) to building interplanetary ships - and colonize our own solar system (our own back yard, so to speak).
This achievement will alleviate population pressure/resource scarcity for the next thousands of years - during which time we will develop technologically.
The resources of a solar system are vast, but ultimately limited.
As you said one motivaton in colonization has been, historically, resource scarcity - of course, it was not the only motivation; not even close.
After thousands of years, population pressure and resource scarcity will impose a vigurous space colonization program - of course, space colonization could have begun long before that point, due to various "motivations".
Is it possible that we will self-destruct tomorrow/in the next decades/due to population pressure and resource scarcity? Yes - the cold war is testimony to that. One of the proposed solutions for the Fermi Paradox
is that all species self-destruct once they reach a certain point in their development. Another solution is that intelligent/technological life is extremely scarce. And there are other, more "unorthodox" solutions.
But it's also possible we won't self-destruct at all.
I mentioned the 1500-now example to exemplify how fast cultures can change/how fast population can grow, given adecvate resources.
And a colonization ship can carry tens of thousands of colonists (this is a timid estimation
) - most of whom could very vell be "frozen" (or something similar). Also, don't think these colonists won't have the means (technological or otherwise) to reproduce/increase their numbers rapidly, if they so wished - of course, they shouldn't have the motivation to increase their numbers by such means beyond what is needed for their safety/prosperity.
About "space wars" - when we're talking about interstellar civilizations:
- the civilizations are at about the same level - in which case neither will gain an advantage - meaning both will continue to exist/expand.
- one civilization is far more advanced than another - in which case this civilization could destroy the opposing one (a task which will take centuries/millenia at the very least!) - meaning the more advanced civilization will continue to exist/expand.
It's worth mentioning that the less advanced civilization could survive simply by sending near-lightspeed colonizing ships in the direction opposite to the more advanced civilization.
As you see, in no possible scenario will alien life disappear.
If AIs destroyed their organic creators, these AIs would take their place and become a space-faring civilization.
About gene-manipulation - why would this lead to the demise of a species? Could you elaborate?
And about the Fermi paradox/Drake equation:
Yes - why are the aliens not here, when they should be here, according to what we know about physics, chemistry and probability?
The truth is - we don't know. Several explanations were offered, but none was truly convincing.
The light speed limit, though, is NOT a viable explanation.