1. If the police merely ask me to go to a police station to assist with their investigation, am I obliged to go? Can they detain me inside the station?
When you are simply asked to assist in an investigation, you are under no legal obligation to assist or go to the police station. You are free to decide whether you wish to assist on a voluntary basis, and you may choose to leave at any time. However, if the police formally arrest you, then you must go with them to the police station (see Question 2 of Part E on your rights upon an arrest).