From what I can gather, the errors mostly occur when the game is trying to process more than one task at once, i.e. if you have "loot one sack" from someone and "loot 5 sacks" from somebody else. More often than not, if you have multiple tasks with the same objective going on, the error occurs. Same with "buy from merchant" from multiple people, as soon as you meet the merchant, the game starts spinning freely.
Solution would be to completely ignore tasks for now and level the rep with gifts alone, which I found no problem once we realise that crafting hides from rabbit pelt is bugged and you can repeat ad infinitum, sell 200 hides to the merchant and just buy whatever you need.
Interesting game so far, it's going on my list.