Ikarius - I didn't hear you mention the three enemies outside the western gate (two skeletons and a zombie). That should easily be handleable at level 3 with both companions. That's actually the easiest way to go (aside from the graveyard tunnel). You did find that other exit, didn't you?
If you did not, all the other encounters you listed are level 5 or so, so yes you will likely struggle a little with them at level 3.
I agree that combat targeting could be improved and it is too fiddly now.
The enchanter is based around crowd control - particularly stun and freeze. It works best with a character who can is Immune to stun and can take advantage of electrified surfaces to attack helpless enemies.
Arhu the mage sells fire spells. He is in the upstairs Legion HQ. Maybe you didn't talk to him because he was in cat form.
