The 5share limit of the bank pool, does it mean there may only exist 5 shares of a corporation or you may sell max 5 shares at a time to the bank?
At max 5 shares in the bank pool.
If A have 30% shares and B 20% shares is it possible to drop the company onto player B?
Depends on where the other 50% are.
If there are already 40% or 50% in the bank pool, A can't sell the 20% needed to to transfer directorship.
But in many cases, some of the other shares might still be in the initial offering, or in the hands of other players.