I'm not a big fan of minimum level requirements on quests. I love how Andor's Trail is totally non-linear. You go where you want to go, no limits. I think this level limit would make the game too linear. I also think it isn't necessary since its kind of obvious anyway when you come across an enemy who is way out of your league.
I'm not saying its a horrible idea, it just doesn't seem to fit AT's style.