Get to the seer as soon as possible and start getting pilgrimage assignments every month. Don't try to satisfy each quest as you get it, plan on having a book full of unsatisfied quests. Killing peasants and getting bones and selling bones lowers your reputation. The game is pseudo-linear. You can usually find quest items ahead of schedule, but not all the quest people.
Reputation is a different story.
In short, just don't plan on mastering in Dark Magic because you reputation will be ruined.