On all locations, read "assigned to" as "at".
For example: The Location Cemetery says "Villains and Minions assigned to this location gain +1 But-Kicking" means if a Villain or Minion is on this Location he gains +1 BK.
Can you change one of your own locations during play. Say I started with "Power Station" in play, can I exchange that with "Streets of Sunnydale" later in the game?
Only using the Anywhere But Here action card.
Pool of Blood says, that if a character defeating the Master Returns at this location you get one extra destiny point. Now this means if an opponent solves the Challenge at this location will I get the extra Destiny point or the controller of the character that has the demonology trait.
On locations, the word "you" applies to any player, not the owner of the location. So if an opponent completes that challenge at your Pool of Blood, the opponent, not you, gets the extra point. The person that defeats the challenge at the Pool of Blood gets the extra destiny point. So if your opponent gets the challenge complete before you do then they would get the extra point.
Is the park adjacent to everything?
Yes the park is adjacent to all locations. (this includes the Nest for non movement things)
You only fatigue if you move from the park to your opponent's location. Do you also fatigue if you move to the park?
No, just from the park to opponent’s location.
The park and blank location spaces do not have any traits.
You move into one of your opponent's locations from the Park, via Fast Pace or Demon Hunting, does the character still fatigue?
Yes as you are still moving from the park to an opponent's location.
These work the same as Biazzaro characters, and are not the same as their real world counterparts. I.e. the Bizzaro Bronze and The Bronze are two distinct and Unique locations and so you can not play Mayhem at the Bronze challenge at the bizzaro bronze
Unless the location states otherwise (Assigned to, at this… etc), characters do not need to be at the location to use the location’s game text. E.g. Your Initiative character does NOT have to be located at the Initiative Base in order to use the location's text.