It's interesting to see where people draw their own personal lines. I don't tend to judge people in that, though if they impose those views I generally have something to say about it.
There's no biblical prohibition against donating blood. It's taking the alleged "principle" of accepting transfusions to a further degree, IMHO adding to the "law" as did the pharisees. I'd personally place the sanctity of life above an ancient dietary regulation, but that's my call. Besides, just what is the difference between DFing and DAing
There are many voluntary acts in life. There are many clearly identified "sins", biblically speaking. How do you judge which is greater or lesser and which you will or will not partake of? Is it a sin to voluntarily watch an R-rated movie, and even worse to do so with others present?
I was an Elder and on the fast-track to CO. After entertaining ideas of reform for a while I abandoned the idea in favour of sanity. The longer you sear your conscience the harder it is to see things clearly - is that not what they say?
Good luck in your moralising - at some point you will likely regret it deeply. Nonetheless, I'm glad to see you around, and I'd happily share a beer with ya