Both prices on the website are inclusive of subsidy. 
India doesn’t have a data protection law yet, but we are complying with all legal requirements for security. You can refer to the terms and we do not sell your date
The 450X, when purchased either way, has warranty. The scooter has 3 years warranty, and the Battery warranty is infinite for subscription and 3 years unlimited kms for upfront.
Not at all, you do own the scooter. You just leave the maintenance to us. If your battery health dips below 80% anytime, we replace it for you.
Further, the monthly fee includes Ather Charge (covering data connectivity, all data costs, data pipeline and storage costs, OTA updates and unlimited public charging).
We do not sell your data to any third parties. The data collected is to improve your experience, and provide services like ride statistics and predicted range. We’ve written about this previously here: A Full-er Stack: Building a data pipeline inside and outside a vehicle