1. http://telecom.economictimes.indiatimes.com/news/reliance-jio-4g-sims-to-be-available-from-april-first-week-4g-voice-data-plans-revealed/51594409?photo_id=51139882
2. I don't think so
3. It will be cheaper than Airtel/Vodafone et all, but still not cheap enough to be used as a replacement...