I imagine the party members actions will be something along the lines of BG/BG2. Your party members in those games would up and leave if they disagreed with your actions, insult each other, offer differing views on what to do according to their alignment, and even kill each other off.
As I recall, this was based on a system of reputation. Doing good and heroic deeds made the general populace regard you with respect, with the advantage of lowering the cost of equipment etc. On the other hand, being villanous caused you to be despised with the opposite effect on the people. If your rep fell too far, paladins would leave you or refuse to join, too high and evil NPCs would leave or refuse to join. Sound familiar?