A couple of thoughts:
I began having serious doubts first, which shook my husband up, but I brought up issues a bit at a time, and he would think about them later (according to him). One of the issues I had was with blood (as you mentioned). I asked my husband how it could be okay to accept fractions of blood, if the only thing that was supposed to be done with blood was pour it out on the ground. If we accept blood fractions, aren't we encouraging people to break God's law?
The other question I asked him was: How did he plan to explain to people in the door-to-door work the change in the understanding of the generation. As you mentioned, we spent many, many years insisting that we could absolutely prove, from the Bible, that the generation alive in 1914 would not pass away before the end came. What do we say now? Why should they have any confidence that our new explanation is worth anything more than the old one?
I wish you the best. My husband and I are both out now.
Cate