> Each of those can be fixed with practice.
Practice can and should be done before giving the presentation to the public. You should record yourself and watch it back.
If you consider practice to just be giving presentations in front of people at a conference, I'm sorry, but no. For example, if you want general practice: seek out your local Toastmasters.
> Your donts are all about nervous people lacking experience.
They aren't. Many of them has nothing to do with lacking experience.
> You don't need notes or a script,
Technically, no, but that's like saying you technically don't need a windshield on a car, or doors, or numerous other things. I have no issue getting up and giving a presentation, and I still use notes.
> Most importantly though, it's okay to screw up when you're nervous and each of these donts is totally fine.
It depends on the context. I'm sorry, but using a conference as your means of practicing is not considerate. People spent money to be there. Often thousands in tickets, travel, and hotels. Speakers frequently get compensated as well. So no, it's not totally fine.
At a local meetup which is usually free? Sure. At some presentation you give at work? Great. There are numerous other ways to get practice, but the context of this thread is conference talks.
As someone who has helped people become speakers at conferences and colleges, I think rather than babying them, it's important to provide clear and actionable guidance.