Ok you are talking about the rogue class so i have some advice. If you are using a up in your face approach without a good stealth skill, you will get beat. Stealth is where the rogues shine. I know that the bosses are a bit overpowered and annoying, but i use a rogue so i have some tactics.
-First get a recruit that is a priest with hardiness skill. Let them cast that on you whenever you are going in the wilderness to quest. It will last 5 minutes and will give you insane health and make you regenerate fast too. Use that whenever you go to fight a boss. Dont bring the priest with you though.
-Second, get a warrior with tanking abilities (high level, good weapon, maybe shield). Let him come with you but make sure that the priest gives him the hardiness blessing as well before you leave.
-Third and final. Try and get as many enemies away from the boss and kill them before you fight him. With a high level stealth, dagger mastery, good dagger and damage skill-storm him while your warrior tanks him and gets his attention. Use your highest damage attacks on him while your 5 seconds of stealth are there.
That should take him out, but worse comes to worse you can always go back to the teleporter to go back to town and heal while he is weakened. Make sure whenever you fight as a rogue to use stealth before you attack. If you just rush in kill everything without a plan, the warrior is better at that. Wizards can kill enemies from afar but are weak as anything when hit. Priests can take many hits, but arent very offensive. Each of these classes have their strengths and weaknesses but i think that none are less balanced. Its all a matter of taste.
The game does have some weird balancing issues that need to be addressed but i think shadow will be working on them soon as dins expansion pack is out of beta. Dins is actually much more balanced than dop, but they are both great games.