I guess you are referring to coil whine, alternatively bad fan bearing. The noise is normal, but to an extent. How recent was that? If it was in the week prior, I’d return it.

Look up motherboard specifications online? Question unclear.

Just take it out and connect it to a computer lol.

Yes, but you don’t really need 1kW PSU, anything 750W+ would be fine, and you save some money and you could upgrade your cpu for example.

The device pulls what it needs, the (maximum) wattage doesn’t matter in such a case.

It’s not required, but it’s nice.