We use it as primarily a file sharing thing. We do not use it for video calls (and I woulnd't recomment it for that purpose).Last time I tried integrating with an office suite server was also a pain in the ass. I do use its calendar and dav addressbook because it works fairly well.

The only security thing we've done is disable a few paths in the web configuration and only allow SSO logins. (Authentik). You can also put it behind Authentik's embedded proxy for more security. I didn't do it because of the use case with generic calendar/addresbook software.

Hetzner is good. Great even, in terms of what you get for the money. They do provide mostly professional service. You will not get one iota of extra service other than what they promise. VERY German in that regard and very unapologetic about it. And don't talk about them in public with your real identity attached. They ban people for arbitrary reasons and have their uber fans (children with a 4 dollar vps) convince other fellow users that if you got banned you must have been a Russian hacker trying to infiltrate the Hague.