1 and 2 should run with any S3 compatible storage. It's not enough to just store the data though - there is also some logic (docker based server) and a database (for ownership, payments..) required. So you need a place to run those as well.

I wanted to build (3) this on serverless components without having to run a docker container and a database anywhere. That's why I implemented that Cloudflare based project and it's APIs are not directly compatible. 

This could be done similiarly on AWS mit Lambda Functions, Dynamo DB and S3. 

 Yeah I understand that it is not just S3. I was just wondering about swapping the object storage layer for Minio or StorJ.  

 Yeah you can configure your own s3 storage in the config: https://github.com/hzrd149/blossom-server/blob/master/config.example.yml#L37