@Jamesjiao not true. I ALWAYS make sure to have a conjuror in my party because they are the ONLY class which can KO the Aetherguard (with banish). Also, when fighting the corruptor in the first normal campaign, you can get rid of his summonings using the Conjuror. Furthermore, having a manasprite in the back ranks is infinitely useful.
now for advice:
1) Do not EVER underestimate the power of buffs such as ranger's swiftness, cleric's holy light, etc. I cannot count the times that buffs like that have saved me in an otherwise impossible fight.
2) Back row clerics are safe from hard-hitting frontliners and if you concentrate their equipment on power regeneration, you can get a heal every turn. This is easiest to do in survival.
3) Anoint+rogue = pwnage.
@kittyfox, the game is not random at all, unless you're playing by closing your eyes and hitting random buttons. Second of all, nobody's making you play the version where you lose your equips, then again, if you close your eyes and click past the screen where you choose difficulty, then that might be a problem.
@iamthepwner the point is for people who have brains (which does not include you) to play a DnD style dungeon diving campaign. Of course, if the only part of games which appeal to you are bright colors and loud explosions, you shouldn't play this game.