I think there's some confusion over which area is being problematic.
1) Right before you ENTER the Castle Bluerock, there's a small blue wall with a few archers and traps. It's on the map
here
The warrior skill Charge can help cross the traps. Rogues have a better chance to disarm them. Everyone else has to work extra hard
As stated above, trying to lure the archers away from the traps can help. Getting a summon / Companion to fight the archers and sitting off the traps can help.
2) Right INSIDE Bluerock Castle, there's a hallway guarded by archers and traps. It's well known as a painful hallway. There's several ways to get past it, but they fall into two general tactics:
A) Go slow killing enemies and disarming traps as they appear (require bow, range attacks).
B) Run through the hall as fast possible, (Charge will help), and getting far enough past the hallway for your Companion to teleport to you. The traps will be problematic as they can slow you down as the archers kill you.
In either option, telling your Companion to stay put while you take care of the first trap / enemy and running back to safety will help.
Bluerock Castle is a huge step-up in difficulty when you first reach it. With practice, and a little increase in equipment and levels, it becomes much easier.