Speaking as someone who did a lot of competitive public speaking back in the day, the frisson of "panic" just before you start is your friend . I'm worried if I don't feel it. As for the rest of the advice, it's probably good advice on how not to royally suck, but not on how to actually be great. That said, your competition will probably not be that good. (The fact that Steve Jobs's keynotes are/were held in such hig…
My background is singing professionally (in the past) rather than speaking, but it's fairly similar for the sake of this point.
I agree with the adrenaline being your friend, but disagree that not feeling it is a bad sign. I always found that the amount of adrenaline/panic correlated mostly with the importance of the performance, and a little to do with what the performance was. When it came it was a friend to embrace not ignore, when it didn't it just meant (for me) that it was an easier gig, and I could do as good a job without any emotions boiling up.