Ya ok now I'm just getting mad about it. WTF are you supposed to do with a rogue character when you get into a fight with 7 enemies!?!?!?
I too was a little surprised at the jump in difficulty between the tutorial dungeon and the first set of battles outside of town. But it gets easier once you learn the element interactions, using choke points, and your characters have a wide enough variety of skills to rotate (which for me was around lvl 5)
As Hannibal mentioned, don't listen to the people playing Lone Wolf parties. They have likely re-played the demo multiple times. Its best to learn the game with a full 4 member party. And if you want an easy go at it, play a Knight/Cleric combo so you'll have plenty of healing and tanking. If you want a good variety go Caster/Ranger, as the two companions you get are Healer/Tank. And be careful when you have conversations early on, as your decisions will effect your parties utility. Bonuses to sneak, lucky charm, bartering, etc. can be planned for ahead of time, saving points for offensive skills instead. My advice is quick save before EVERY conversation and re-load, to figure out which ones give which bonuses.
edit: Also, don't underestimate the power of SNEAKING and finding alternative directions to approach a non-surprise encounter. You can sneak close and set up barriers like boxes to help deal with archers and stuff. Also, a good witch/scoundrel back stabber can do wonders when geared right, I hear.
edit 2: Oh, and scrolls.... scroll, scroll, scroll!! Any party member can use them and they are cast at default 100% effectiveness.
edit 3 (sorry): Boss battles can be run away from and re-initiated later, after a re-gear up. That is the way I beat the light tower battle at level 4. I don't want to spoiler anything but I will say WTF that is a hell of a fight. I had to retreat and come back fresh
twice.