(1) yes i do think it exists.i dont know when humans will discover it.
(2) i dont know
(3) i run it for two reasons
(1) to join in and search for ETs
(2) to keep my computer working when its idle
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.