So I go to this dungeon that is beyond rediculous with creatures I have no chance of killing. I somehow find the main creature and by a miracle kill it. There are tons of magic walls and all kinds of stuff. I make it out alive with a TON is really nice loot. Got myself nearly a full set of Elven armor, a number of magic items to have identified, an awesome sword that kills all humanoid creatures with a couple of hits. I'm feeling pretty proud and extremely excited. I go to the mage's headquarters to report that I've finished the quest and every time I take the reward gold and click "Exit", my game crashes. I'm NOT giving up this stuff.

Questions:

Is it worth it to take a hit on reputation?
Will I ever be able to get a quest from the Daggerfall Mage's guild if I don't "finish" the quest in time?
What could be causing this problem?

1. You only lose 2 points of reputation, so yes, keeping all that stuff is certainly worth the reputation loss.
2. Failing a quest will not make future quests impossible to take on. The only things that happen when you fail a quest are that you don't get the reward provided by the associated faction/individual and you lose those 2 reputation points. Successful quests provide 5 reputation points and you can always do future quests for somebody... no matter how many previous quests you complete and/or fail.
3. I'm not sure, but the game doesn't have the nickname of Buggerfall for no reason.