As for the blood issue:
jwfact.com does an excellent breakdown of the actual scriptural statements on the use of blood. Really worth a read.
Not to mention that the JW stance on blood is completely hypocritical as fractions and medications that require liters upon liters of stored blood to produce and add up to 100% of whole blood are allowed. Not to mention that the organization has flip-flopped multiple times on this issue.
I have a question for you? What is more important, the symbol of something or the actual thing? For example, what is more important, the symbol of marriage (for example, wedding rings) or marriage itself? What is more important, the symbol of life or life itself?
How do you think the God of all mercy and the giver of life would feel about parents sacrificing the life of their children over a symbol?
If you read the gospel accounts, you will see that Jesus consistently put human life above the law and gave many examples and parables about this exact subject. Jesus stated that the Sabbath was created for the sake of man, not man for the sake of the Sabbath (Mark 2:27). Further Jesus stated, "Go, then, and learn what this means: 'I want mercy and not sacrifice'" (Matthew 9:13). Jesus further said that it is not what goes into a man that defiles a man, but what comes out of a man that defiles him (Matthew 15:11).
Moreover, the pouring out of blood is always done in connection with the death of that animal. It is to show respect for the life of that animal and respect that life comes from Jehovah. There is no way to fully bleed an animal, but pouring out the blood was symbolic for that dead animal's life (Leviticus 17:13, 14; Deuteronomy 12:15, 16). Consuming no blood was not the point as that is impossible, but rather the symbol showing respect. This is highlighted when David poured out, not blood, but water, showing respect for the life of his men (2 Samuel 23:15-17).
Further, blood transfusions are a totally different scenario, as no life is lost when blood is donated. There is no blood to pour out in respect for lost life as no life is lost. In fact, life is often saved, which is the highlight of respect for life.
Finally, Acts 15 read in context and in context with other scriptures makes it clear that this was a one time compromise to make peace between Jewish and Gentile Christians. Jewish Christians were trying to force Gentile Christians to adhere to Mosaic Law and this was a compromise for the sake of peace and unity. Paul and Jesus Christ himself both make it clear elsewhere that eating things sacrificed to idols and in fact eating anything was not a sin (Acts chapter 15; 1 Corinthians chapter 8; Romans chapter 14; Mark 7:15-19).
The point is, the JW stance on blood transfusions is unscriptural and perverts the message and purpose of Christ. It does create human sacrifices and martyrs, which is what the organization wants. Once you find out the truth about the truth, you will see that the organization does not care about the flock, the "rank and file" Jehovah's Witness, and will gladly sacrifice them if it suits the organization's purposes. The blood issue is just one example. How many innocents died due to the former stance on vaccines and organ transplants? On selective service? In Malawi (research Malawi vs Mexico)? There is so much more. I suggest you research more both about Jehovah's Witnesses and about the Scriptures.