Thanks!!
I feel a bit more confident about this project now. To know that I'm on the right track is very validating to me. I will do my best to do my proper research and not go balls to the wall on this one.
I also really appreciate your advice on security, as I think this is the leg from which I limp the most. I'm still very new to all SSH and HTTPS things, so yeah...
I also didn't quite understand your first point; what does openhab mean? And how is it possible that the people you mention aren't getting hacked? Is it related to the second point about using ssh keys? I read in another comment that hackers could compromise my home network if I'm not careful enough, so I want to be extra cautious with that. (I hope I'm not lacking in common sense... perhaps it's my reading comprehension that's lacking... Yeah, that must be it!)