>>I am not a doctor but I would think there is some period of time between when symptoms physiologically begin, and when you feel you're having symptoms.
Most physicians consider symptoms to have been noted by the patient.
>>So I have to question the "no symptoms - zero transmission rate", because the latter is precise and the former is not.
Actually the former is precise also. Asymptomatic means the patient has not experienced symptoms. In the case of Ebola, the experts say that there's no virus detectable in the bloodstream before onset of symptoms.
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1