What’s recommended is amazon S3 which is an object storage not block storage not block storage.
It is recommended to serve the static files in case You’re looking to save some space on the Host system’s disk. What You can do is upload to s3 and configure a Cloudfront CDN to the bucket and use it as Your URL.
In other case, S3 is also used to save the system backup which is useful in case Your forum has some techincal difficulty and you need a backup to save Your day.
Simple answer, No, It’s not, it includes a lot of downtime and efforts to migrate images and stuffs back & forth so You should be pretty confident about what path you want to take.
I don’t understand if You’re talking about the core files or media but if You’re installing the docker image, all You can do is either use the Discourse admin panel or ssh into the machine and enter the discourse app to do any modifications. Which is Not recommended and isn’t a Good approach as any consecutive updates may revert any changes made by You.
Indeed, Discourse is best.
NO, DISCOURSE DOES NOT RECOMMEND ANY BLOCK STORAGE. S3 is indeed an object storage and not block storage,
Refer this: Object Storage vs. Block Storage Services | DigitalOcean