"DJ - Jehovah God says "abstain ... from blood" (Acts 15:20). Jehovah says you may not use whole blood. By this command, He also prohibits the use of any of the four components of whole blood. But Jehovah has no policy against your using fractions from any of these four components. These fractions constitute neither whole blood nor any of the four components of whole blood."
Your illustration is very clear and it comes down to the laws that are laid out by the owner of the music, those laws are also very specific and allow the consumer to know when they are breaking the law. The owner has also provided some limited useage of that music at no cost.
The bible, God's word announces only one rule - 'abstain from blood' (as to whether this means eating or injecting is another matter), there is no leeway, it doesn't provide for extractions from blood, that is what parts can be used and what can't be used. So the owner has been quite clear. But according to the JWs he has passed some authority to the F& DS and a select few from that group have decided that they have the authority to fine tune that law of abstaining from blood.
You say that it is Jehovah that has no policy against using any of the fractions of the blood but I strongly argue that if this is the case then there is also no policy against the use of any of the four components.
To take this further, in theory a scientist could estract fractions from all four components and come up with quite a powerful 'nutrient' rich agent and in doing so may prove much more beneficial than just injecting one component for certain medical conditions. He would even be able to target the fractions that are the only parts necessary for the medical condition without the need to use the whole blood. Although he hasn't created a new component he has created something better than one individual component.
In your example of the music this can also be done by compiling the samples together in such a way that it becomes a medley and is marketed as a new track and possibly has the same laws applied to it.
I guess it all comes down to the fact that the GB have made their own decisions on this matter. However, if they feel that using fractions are up to a persons conscience then for the same reasons that they come to this conclusion can be used to say the same for components. The difference is that you can just accept what the GB says, without question but non JWs can stand back and see that there is no logical cohesion with their conclusion.
The example of the coffee is interesting because I would consider why the mother has forbidden the child to have coffee. It could be that they react very badly to consuming caffeine. Even that minute amount that the child ended up comnsuming may cause a reaction. In that case she would likely throw out the coffee machine and because she could not trust her child to understand that he must avoid any amount of coffee also takes the step of eliminating all coffee from the house. Unfortunately there are still circumstances outside her house where she has no control and she can only teach her child how to avoid coffee (and anything else that may contain caffeine).
One might consider that the GB is simply training the conscience of the JW in abstaining from blood but what they have done is say that some parts of it are okay (if the individual feels such) but major parts of it are not. That is not what God said and no amount of fine tuning that law would bring one to that conclusion.
What the individual can do (or the GB) when considering the issue of abstaining from blood is to look at the principles and circumstances behind the law and that will help determine whether injecting blood (from another human who has not died and life is still in him) is the same as eating blood from a dead animal.