1. The universe is too big for one lifeform. But the universe is also too big for interactions of these lifeforms. Perhaps we'll find some bacteries on Mars, Jupiter's moon Europa or comets. But it will be all. These discoveries of simple extraterrestrial organisms will be exciting and some religions might fail. But I believe that there is at least one other inteligent civilisation. The civilisation that is able to contact us. This possibility makes SETI project revelant for future of humankind. But is our world prepared for such future? Actually I don't know...
2. I think that it's not necessary. Wireless comunication is also transmitted to the outer space. It makes our solar system unique for other civilisations.
3. Idea to use bilions of personal computers all over the world for computing of scientifical data means revolution in scientifical research. It's the reason for running SETI@home on my machine.
SETI@home and Astropulse are funded by grants from the National Science Foundation, NASA, and donations from SETI@home volunteers. AstroPulse is funded in part by the NSF through grant AST-0307956.