Once you gain some experience, 4 is the only one I would say is a hard rule. Experience will teach you how to break all of the other rules effectively, as every other rule entirely depends on context. The main reason why tech talks are boring are two reasons - inexperienced presenters, and that engaging talks take time to prepare.
One tip I'll give for people is don't rely a script. If you have a script, you're writing emotion and adaptability out of it. Teaching content is a dance with the audience - you have to adapt to how they respond in order to present effectively. Give yourself an outline, and in your head run through twenty different ways you'd present that information to people. Knowing how to dynamically present your slides means you can engage with your audience far better and you can take time to read the room. If you present a talk twice, it should be different each time as the context changes.