There is lots and lots of competition inside species which makes it stronger as a whole.
Based on what evidence? The human race has been competing with itself for the last 3'000 years - and look what its done to us, our moralities, beliefs, relationships, and even the planet itself. Gaza, Rwanda, WWII, anyone? Have we become a stronger race for it? I don't think so. And no, building bigger bombs doesn't make you stronger, it just makes you more liable to do something really stupid.
I'll give you an example about competition inside spicies: there is one attractive girl, and you and I go after her. To deny that this kind of competition doesn't make the spices stronger is kinda naive (and I'll get the girl
Those examples you mentioned are more of a tribe vs tribe, or system vs system. And, yes, bigger bombs make you stronger, there is no way around it.
I know you're invoking natural selection here - the idea that the strong survive by getting rid of the weak. What evolutionists fail to realise is that even the "weak" species play fundamental roles. Earthworms, for instance, aren't particularly strong, and would lose in just about any fight - but without them, our soils wouldn't be nearly as fertile as what they are.
Just remember that the purpose of the theory of natural selection was to explain how the current species spread came to be. In Dyson, we already know exactly how the species is to behave, the environment it will act in, how it will need to respond to stimuli, and how it will reproduce and spread. Introducing further competiton at this point is insanity - all it will do is promote counter-productive individualism, which (as I'm sure you've learned when you need 400+ seedlings to take an asteroid) will severely hamper your efforts.
Hm, who said that evolution is about survival of the strongest? "The strong survive by getting rid of the weak"? No, the strong survive by controling the weak. Major difference. Wolves don't get rid of all the rabbits. They simply eat them. Why? Because they can. The wolf has more control over the rabbit, than a rabbit has over wolf.
edit: Also don't listen to Wogan who thinks that he knows components of asteroids The word "asteroid" here is used to describe the round things on which trees live, they could very well be in alternative universe whith different minerals than our own.
Still with the alternate-universe thing? I honestly can't see why it has to be that way - we have plenty of asteroids in our own universe already. Just because they're represented with circles in the game doesn't mean that they're circles in real life 
Plus, it was a scientist in this universe that proposed the idea, and an author in this universe who proposed the technology.
This is not about who is right or wrong, but which one would be more interesting to play. You are forgetting that this is all in context of a game. I say that playing as a tribe vs tribe will be more interesting that playing as you suggested. The platfrom is ready and it introduces huge ammount of possibilities to expand the gameplay in the future, like hero dysons, rogue trees, friendly tribes, neutral spicies, food chain and so on.
PS: please split your posts, its getting harder to answer them if you put all the stuff in one post.
