ad 1) In Trial you should have all the professional features available. After trial they will become inactive. You can identify your subscription status in the ribbon in the top left corner.
ad2) All data, including media files, are stored in Amazon S3 (AWS). As a market leader AWS provide highest possible security standards (https://docs.aws.amazon.com/whitepapers/latest/aws-overview/security-and-compliance.html). Their systems have one of the most advanced security schemes implemented and they are regularly reviewed. No need to say that data stored in AWS are probably better secured than anywhere else. AIRe Link also passes regular security oriented tests - automated and manual. We passed last penetration tests in April 2021.
ad 3) The pricing info and review is currently on the way. With the next release it should be aligned. Next release is planned for next week.