Might be related to those sleep state stuff that microsoft keep pushing. I think LTT has a video about how it causes battery to drain while off. I think the solution was either shutting it down while unplugged, or while plugged in or something. If you always shut the laptop down with the charger plugged in try to unplug the charger before shutting it down and see if it makes a difference. Or the opposite. I don’t remember which it was.

To be fair I haven’t configured a firewall either on my laptop. But that’s out of lazyness, not out of good practice. Good practice would be to have a firewall enabled. Just because something is unlikely to happen statistically doesn’t mean it’s bad practice to take steps to protect against it.

I fail to see why this is bad advice. Sure you could just disable the firewall on your computer on a local network. But that’s under the assumption that you can trust everything on your local network. What if it’s a laptop? Do you also trust any public networks you may connect to on the go? Having firewall both on the router and on your computer provides an additional layer of security, and I think that’s good advice in general. You can for example set it up to only allow incoming connections when connected to your home network for example.