And that's exactly the problem... we don't know what we don't know. We are assuming life exists only in the form that we have encountered it on Earth. And we're assuming that just because we can't find something, that it isn't there. We are taking all things solely from our perspective and we are convinced that they can't be any other way. This seems extremely egocentric and could be disastrous when encounter something far outside of our narrow perspective.
And what if we find a bacteria on Titan that lives beneath the surface but is harmful to humans, will we exterminate it for our own sake? What level of intelligence is required before we attribute value to another species.
As far as rights are concerned, this is a real issue. If the first country to Titan plants a flag and then says, "This moon is ours". Does that make it theirs? Will countries fight wars to protect their perceived rights to a particular moon? It may be arbitrary but that doesn't mean it isn't real. National boarders are arbitrary but they are very real. But in the same case as with countries, what gives us the right as a species to go a moon and claim it. Is it a right based on force, an ethical right, a right of first claim? The very idea of colonization assumes certain rights. The question is what are those rights based on?
And no I'm not trolling. It's sad that we are prepared to discuss ideas without being prepared to discuss the underlying philosophies. I'm simply saying that before we consider what to colonize or how, we should consider whether the very notion of space colonization is valid. This isn't a moot point. If we're wrong, at worst it could mean the end of our species. All cases of colonization on earth have lead to genocide or war... no exceptions. Why do we think space colonization will be different?