But the big doctrinal stuff doesn't change. Which is important to me.
reniaa, I can understand and respect your choice to be a witness by this criteria. Do you, in turn, understand why that criteria would not be enough for someone else?
For example, let's take the blood doctrine. Now, I don't wish to debate whether or not it's biblical; there are other threads for that. Suffice to say, persons such as yourself believe that it is necessary to avoid blood transfusions to please God. Whereas other persons believe that sacrificing a human life for the sake of avoiding blood is a great affront to God. To this person, that is a major doctrine which would convince them that the Witnesses do not have God's backing. To a witness, perhaps this doctrine isn't that big a deal. They have found other teachings they agree with, so they go along with this one as well. To someone for whom the doctrine is a big deal, there is no overlooking it.
If someone were to find this doctrine morally repugnant, and search for a religion that more closely matches their beliefs of what God has laid out in the Bible, is it reasonable to consider this one wicked?
It's obvious atm we have the bible and holy spirit as guidance
This is not obvious at all. It may be the conclusion you have reached based on your perceptions, but others have reached different conclusions they believe just as firmly, that are also reasonable given the evidence.
I did think of an example of change in the bible not bought about by God and that was moses giving authority to leaders among the tribes to judge in his place his father-in-law gave him that advice and God back it up afterwards.
My contention wasn't that God's human servants could never make decisions without his direction. It was that if God gave his direction, that should be readily apparent, at least some of the time.