@jebus-jones, that will be really cool. I hope you'll do a video showing it off when you get it working.
Right now it's unclear to me whether you've gotten Stringify to talk to TRIGGERcmd yet. Have you seen this article or this article?
You should be able to add a "Connect: Maker" thing and select "Send an HTTP POST" and use a URL like this:
https://www.triggercmd.com/api/Stringify?trigger=Netflix&computer=MediaPC
Now that last scenario, where you're turning on your Media PC, waiting for it to boot, then launching Netflix - that's trickier because you'll need another computer to turn on your Media PC, then you'll need to wait for it to boot, then trigger the next command. Do you have a Raspberry Pi or something on your network? I boot my computer using my Raspberry Pi because it's always on so I can open my garage with it.
Assuming you have Raspberry Pi, you could have it run a bash script that runs wakeonlan to boot the PC, then loops until it gets a successful ping, then runs a curl command to trigger Netflix on the PC.
First thing's first - please tell me if you've gotten Stringify talking to TRIGGERcmd yet.