Yes, very usual for EU companies. Make sure to blank anything sensitive. If this seems weird, consider how many places require your Social Security in US.

Not in my experience. Hetzner is the only one out of a dozen that I recall asking for ID.

It's generally finance related that requires a social security number. If a hosting provider asked they would get 123-12-1234

Yep. OVH (The French) have a pretty strict ID policy too. Nothing to worry about.

I didn't have to provide ID with OVH, just fill out my address.

You must have been lucky then.

I had to go through a manual send photocopy of my ID process etc.

Usually hosters do this so they have some verfied name or address in case of abuse.

> they asked for my passport or id card

This is often for tax reasons -- specifically, whether VAT can be waived.