1. Probably - Logic and the Drake equation indicate it is likely. To assume we are the only life in the universe is both arrogant and fundamentally depressing.
Should discover it within the next 50 to 100 years.
Benefits - shared knowledge, and hope for long term survival.
Dangers - exploitation and corruption by us.
2. Yes - details of our greatest achievements, and a map.
3. Because I want to know.