One thing you forgot to mention (and most people are unaware) is that the little "v" shaped piece of bent metal that's in each terminal acts like a 1-way valve in that when you push the wire in, it hooks it and won't let it back out, but only if you have stripped away enough wire for it to go past the end of the metal. Most people just think about the set screw holding the wire in, but it's the metal clamp that is the saftey. Strip the wire way longer than you need and start pushing it into the terminal to see how far it needs to go. With the screw lightly tightened, pull back and you can feel how the metal locks the wire in. Most failures I see out in the field of wires coming loose are because they didn't strip the wire enough and push it into the terminal far enough to get it "locked" past the metal clamp.
For example,
this person looks like they're unaware of the function of the metal clamp and has not stripped the wire far enough or pushed it past the end of the "v".