Interesting reading there mate. I think you have the right angle on the scripture. I have read this explanation before by amongst others - JanH.
The Watchtower guys take the reading out of context quite clearly and as you say - the blood issue is a matter of personal conscience and not an absolute rule for Christians to obey.
I think most right minded people would not drink blood anyway, as such. This is clearly to my way of thinking, quite perverse (although I am vegetarian as well, which enforces this viewpoint further).
However, as many of us know, using components of blood (the whole part, or fractions of) during a medical procedure is different and could be viewed as "caring & sharing" - helping to preserve life without slaughter. This is also done with full consent. A little different to the blood-letting that took place in some quarters around the time of Christ (whether that be animal or human sacrifice).