Following that link then the next link in the blog did not lead to a scientific study of chickens laying more eggs because they listened to music... but maybe I just missed the real link to the study I ended up at an article talking about a research grant given to someone or another.
Mind don't seem to mind the music and I enjoy it so that's good enough for me.
I use a POE switch that you plug into the wall... then plug my POE cameras into that and view them in a browser. You can run a CAT5/6 cable 300' from the switch. Some of my cameras the CAT6 cable is just laying in the woods...
The control link is for some cloud service not controlling the Rpi over SSH.
Here is some information (from me) on setting up a Rpi, I prefer the lite OS myself but YYMZ. Once the Rpi is setup properly you can open a terminal in another Linux PC on the same LAN and SSH into the Rpi. Then you can run a command line program to open or close the door. You can't run a GUI over SSH.
Did you check out this post on a door?