At least at the starting section of Broken Valley leveling is faster in DKS than it was in D2:ED, so even without boosting the mindread skill, you should not have any problems. I mindread fairly liberally in D2:ED, and didn't have any problems getting to a fairly high level by the end of the game (though certainly wasn't over-leveled early to mid game).
There are places in the FoV section of the game where opponents respawn, but I don't think there are before then (other than possibly the couple places in D2:ED where opponents could respawn: the Aleroth Ministry, when helping Zandalor, and Keara's fortress headquarters, trying to open the door without correctly naming all the statues).
