It's a trivial and unimportant thing, but I can't help but notice that most audio volunteers pronounce H as /χ/ rather than the softer /x/. Perhaps this is because Q is /qχ/ and not /kx/?
It's because that's generally how Dr. Okrand does it. The description in The Klingon Dictionary refers to softer and more generally known sounds, but Dr. Okrand makes the sound more forcefully and further back in the throat.
Do all the actors also pronounce it as a voiceless uvular fricative?
I haven't paid careful enough attention to judge how most of the actors do it. I will say that the actors portraying Morskans do not - but that's a whole different issue!
I wish all the phrases came with this sound track. It would make it easier to understand the spoken words sooner.
The contributors are all volunteers with real jobs, but we are slowly working on getting audio for more and more sentences. Be patient and your wish will be fulfilled.