Hiya, and welcome to PlaneShift! :)
1. Your choice of religions/beliefs does not currently have any influence on anything. However, since choices for religions are available during the character creation process, they are likely to have certain influences in the future. No clue when ;)
2. PvP in-game is purely voluntary - a character offers a /challenge to another, and that other has the option of accepting or refusing. If you got a refusal, you must wait a minute before challenging again, else there will be penalties. When guilds enter wars with each other however (again with both parties accepting the challenge), the guild members are free to strike at each other without further individual /challenges. Dueling in crowded public places is generally frowned upon - but the Hydlaa Arena is perfect for such things, especially large dueling tournaments that have been held before, and will be held in the future.
3. There are no racial tensions in PlaneShift - all the races have been here long enough to learn how to get along, and most cities are multi-racial :) Individual tensions however, certainly exist.
Have fun PlaneShifting!