Federated actions are never truly private, including votes. While it’s inevitable that some people will abuse the vote viewing function to harass people who downvoted them, public votes are useful to identify bot swarms manipulating discussions.

Yes, by default files are stored directly on a volume on the disk but it’s possible to configure pict-rs to use object storage, although there isn’t much documentation for configuring and using it with Lemmy yet. Kbin has support for S3 storage in its environment variables. I’ll do some research and see if I can add it to Lemmy.

Imgur was created as an image host for Reddit back when Reddit did not support direct image uploads, so any self-hostable image storage solution including Lemmy’s built-in pict-rs will work. Federation of the file host is not necessary as there is no need to mirror the files between instances, they are linked to federated posts and the file can be viewed directly on the uploader’s instance. As for the community features of Imgur, the “community” on Imgur is, as one Redditor put it, “the sewer rats who don’t realize they’re living in the sewer”.