I definately believe that there is other life out there just they are not ready to let us in on it. I believe when the time is right they will show us the way. As far as the dangers i dont know, maybe they conquer the world maybe not. I think the benifits would be infinite.
As far as sending a message i think we arent doing enough maybe instead of making war amongst ourselves we should be looking to unite and look into outerspace before ET decides were too warlike and decides to pass us by.
I run seti at home because im curious . i have had a fascination with space since i was a kid and i would like to think maybe we might find someone out there in my lifetime.