As far as resting goes, you should try to cast shadow hound whenever possible, and rest at an area change boundary. If you get attacked by superpowerful monsters, you can simply run to the next area, and they won't follow you. Resting in huts that don't have doors or in crevices is usually a good idea, but can sometimes result in the death of your party, with no chance of escape, if superpowerful monsters find you.
For example, I was resting with a level 10 party in the Monastery-Arnika Road and was awakened by higardi brigands and cultists. The cultists kept casting whipping rocks while the brigands were fighting me and eventually killed my entire party.
Another time I was in the mine area and slept in a hut. A group of helligators attacked my level 12 party and demolished them in no time at all. I couldn't escape.