Well at that point, typing faster on a regular keyboard won't help you very much. You need to learn stenography system, such as Plover which is a much more involved task.
Really? That seems very high. I think I shoot for 10-15...
Ideally, I can measure my speech in wph.
I'm not sure I understand. 15 words per minute means you say one word every 4 seconds.
On reconsideration, I think I'm still estimating too high on the average. I might be a little laconic.