No, we don’t need a Bank PIN.
That depends on the type of your account. If you are playing a normal account, you don’t need to prepare any gear or items; if you play an Ironman account, your character needs to wear the required gear and have some food in the inventory. All the requirement is listed in each item’s description.
No, please don't log in to your account until the order is complete.
Only doing the Pest Control Mini Game will cause your character's Hitpoints to rise, and it is unavoidable. So, make sure you don't mind it before you placing an order.