Is it even possible? I need to run a specific script at every level up, I made a quest that runs at the level increase event but it works only once because at every subsequent iteration the quest is already completed, so the script attached to it doesn't run. Do I need to create 80 quests pointing all to the same script? I'm hoping in a more elegant solution.

I'm guessing you already tried Quest.Reset()?

Does it really work? It's reported as broken in the wiki -- see http://www.creationkit.com/Reset_-_Quest

I'm at work atm, I'll give it a try in a few hours.