This is a really simple OS for x86-1452. Just kidding! This is a ridiculous OS for Raspberry Pi 3. I've answered some key questions below:
Maybe!
I have no idea!
I wanted to suffer.
Proba--absolutely not!
I don't know!
Actually though, go check out bztsrc's tutorial if you want a real tutorial. Or jsandler18's tutorial! Or maybe take a look at this forum, or this one, or even this great OSDev Wiki page. These are how I got started building this cute OS (that might even boot!), and they've put in great work that you should check out. Also much of their code/tutorials was used as a starting point for this, and I'm eternally grateful they put their work online.