So, I was checking out some of the other content in the EE box. Turned out that the game guide has all the answers, including which solution to quests gives the most xp, detailed descriptions how to solve etc.
Ah well, I might just want to not look too much into that one yet. More fun not having a clue what is going to happen, although Alvin is asking some rather badly concealed questions that implies he has a major role to play in the future. I suspect my answers to his questions/dialogues will come back and bite me in the butt later.
Edit: Decided not to sacrifice the prize cow. Some quite funny dialogue with the cow, cow guard and cow buffs there