Here are a few of the questionable claims and actions of the GB that I have noticed:
a. writing themselves into the salvation formula
b. claiming they are Jehovah's unique channel of communication
c. asserting that no one who rejects their authority is a real Christian
d. determining that 99% of those martyred for the name of Christ prior to the 20th century were only professed Christians
e. denying all the benefits of justification to 8 million so called modern other sheep
f. mandating shunning of former Jehovah's Witnesses
g. claiming that those who don’t trust them, don’t trust Jehovah.
Please add to this list.