In Linux you just download, extract, and change the symlink. It is really easy.

Really only if you’re running your own email server. Otherwise as far as I know dynamic DNS fills the need.
You aren’t in any more risk either way.

Sounds like maybe you want to look into pfsense to do traffic filtering. Highly recommend.

Hmm I have none of these issues

No, POE. Just the round black ones, I forget the model.

The only gotcha I can think of is the 4k bandwidth, better make sure you can handle more than one camera on your network.

Not parent, but Zoneminder locally with the zmninja app works pretty well. VPN allows remote access, so it is slightly complicated but not too bad.

Reolink and Zoneminder has been working fine. Put the cameras in a vlan, block their access except to the ZM server, you can use any IP camera.