"But JWs aren't the only ones who interpret Michael to be Jesus."
There's a small amount of truth in that. I believe I heard (this was decades ago, so my memory may be faulty) a Christadelphian say that Jesus was Michael in some prophetic sense. But they wouldn't have had the same belief as JWs, even though Russell probably got his non-Trinitarian views from the Christadelphians. The Christadelphians don't believe in any pre-existance of Jesus before his conception, while Michael was around before that.
The blood doctrine is totally unique to JWs, probably a hobby horse of Franz. You'll note that it wasn't implemented until after Rutherford's death. He was in ill health; perhaps he needed transfusions.
144000 Israelite male virgins referring to Christians of both genders and not being necessarily celibate is unique. The nature of those people is apparently "symbolic", but their number (12×12×1000, extremely symbolic biblical numbers) is apparently absolute.