As far as doctrinal matters that are “unique” to JWs, a lot of them aren’t unique but rather taken from Millerites, which sourced after various schisms and disappointments into Christadelphians, Adventists, various Bible Student denominations and one of those Millerite sects is the WTBTS. They all believe in a soon to be end of day.
I recently learned that Heavens Gate also had similarly millenarian views and evangelical Christian theories that closely aligned with JW/WTBTS/Millerites, they just added UFOs and kool-aid.
CT Russell also had influence from the prevailing spiritualism and Egyptology craze in his neck of the woods which is also where Mormons get some of their stuff.
As far as the Jewish view on blood, they believe that saving life is more sacred than strict adherence to law. The law in Judaism is an ideal guideline more than a strict law, they don’t have the same concept of sin or either current or future divine retribution.