Thanks for a most interesting series of articles. I've been studying the history of the Black Death for a little while now, and mulling over the available evidence that suggests bubonic plague was not actually responsible.
Have you read Mike Baillie's book, New Light On The Black Plague 'the cosmic connection'?
A very thought provoking book, presenting strong evidence that cometary impacts and overhead explosions around the time of the 1340's, was responsible for the mass deaths; this includes all the earthquakes documented at the time, the descriptions of raging fires and 'bad vapours' killing people hours after they inhaled it, trees 'knocked to the ground', the terrifying objects seen in the sky by observers.
I think it's worthy of serious attention, particularly due to the evidence that bubonic plague just couldn't move that fast, and thrive in cold areas.
This article reviews the book and highlights many pertinent points, really worth a read: