The White Washed Wall refered to is that of a tomb, or grave that has been decorated to look nice on the outside, but is filled with dead men's bones. See Matthew 23:27. Contact with the dead would defile the High Priest and prohibit him from officiating at the trial.
Striking a prisoner before conviction was against Jewish law and Paul is pointing out the hypocracy of the High Priest who was willing to break the law in an effort to intimidate Paul, thereby corrupting the judicial process.
Paul received the "Macedonian call" while on his second missionary journey. His first trip to Europe was in response to this call. You can read about when Paul started his second missionary journey in Acts 15:36-41, and when Paul received the "Macedonian call" in Acts 16:6-11, and read about the first convert in Europe in Acts 16:14-15.
Yes, as read about in Acts 21:27. Paul seemed to have this effect on the Jews whenever he mentioned his call to the gentiles.
No, a Priest can not tell anything to anybody.
The priest is generally greeted as 'Father' by the lay people.
A priest in Hindi is called a "pandit" or "pujari."
A French priest is typically referred to as a "prêtre" in French.
The Coercive Acts
A kohen.
Celibate
clergy
Lamas
pari