windows – Remoting into PC from local network only

I’m using a really slow laptop running Windows 10 as a steam link client PC connected to the host via an ethernet cable. Using the regular Steam app on the laptop for Steam Link is just too slow and sluggish. I can boot it up using wake-on-LAN just fine with a WakeMeonLan batch script from the host running Windows 10. The Steam Link windows program then starts automatically (with the help of an AHK script) because I have it as a startup program.

However, I have to go over and type on the laptop keyboard to shut it down whenever I stop playing.
Is there a way to shut it down remotely from the host PC, preferably with a batch script so it’s a one click solution?

Unrelated things that I also want the laptop to do:

What’s the best way to use it as a NAS while still running Steam Link? I’ll turn it off when I don’t need the NAS, probably just use it to store movies or something..

(For security reasons) What’s the best way to have it disconnected from the internet but still be connected to the local network? Every few weeks I’ll need to reconnect to the internet to update (if needed).