It's fairly important, that group admins get an email notification when users try to join a group.
Please open an issue for this on our github.
@sanatisharif someone would need to build a plugin for uploading to minio.io
Maybe to can fork the S3 plugin 🙂
Hmm that would actually be a good fix for this here: https://community.nodebb.org/topic/6582/cooldown-on-group-join-requests/1
Admins can change users passwords now from their account>edit page.