1) that technology will make everything possible given a long enough period of time.
2) Other species will develop the same technologies.
3) Other species will have the same desires as we do.
I see a lot of these assumptions should be looked at more closely.
For example, some of us aren't that confident in technology solving every issue. We are on a collision course right now with ourselves, in my opinion. If I were asked to assume that life would develop in a similar way as we did, then I would say that the reason we don't run into them, is that they don't survive long enough to get to other solar systems. I certainly hope that we don't make it.
I am reminded of the famous quote by Mahatma Gandhi. When he was asked what he thought about 'Western Civilization' he said he thought it would be a good idea. I hope that contact doesn't happen in my lifetime at least. *shudder*