Biggest one: Drop the idea that the Faithful and Discreet slave is God's Channel. They've been wrong, admitted it, and blamed it on God, saying he hadn't shown them the New Light yet. Sometimes they even suggest that God purposely fed them the wrong idea because it was better for them to think it at the time, then fed them the truth later. This is such a counter-intuitive, mind-controlling doctrine, that one alone would take several down with it.
If they let the Bible decide what's shun'able and what isn't, and only make suggestions about the rest, that would help. Make blood, holidays, beards, all their little pharisetic rules into articles along the lines of "we think this is how God might feel about it, but you make up your own minds."
Drop the counting time stuff. It only serves to divide the congregation, make people feel guilty, etc. Like Israel, just let people contribute what their heart compels them to.
Shun unrepentant sinners (genuine sinners, not "apostates"), but immediately welcome them back when they say they are repentant, following the example of jesus' prodigal son illustration. And no judicial committees, the shunning would be done by each person individually. (I'd prefer they drop the DF/shunning thing altogether, but they're Bible followers and it does seem to teach this. But it sounds like warnings to individuals, not the basis for an organization-level doctrine.)
Let the police handle child abuse accusations.
One meeting a week.
Stop bragging on themselves at every turn. "Only God's people have the ability to do [whatever]!" "Only in God's organization do we see such fine spiritual people!" That sort of crap. Knock that off, it's embarrasing to listen to even if it were true. All the more so since it clearly isn't.
Reduce the scheduled studying. One meeting a week would help this. Give the members their lives back so they don't feel like they are on a never-ending chain of meetings/service/study.
Dave