I really enjoyed this quest from an immersion standpoint!
At first I was sad that as a rogue, I couldn't just pick the lock.. but of course perhaps they took my picks.
I had a laugh at the possible items to click in the cell, the idea that a torch holding a secret switch would for ANY reason be inside a prison cell lol!
The controlling of the hand is intentionally awkward. You can't strafe! You're just a hand walking on fingers and it's your character's first time being a necromancer after all! The trick is - you need to remember that you turn slowly, and you need to face the right way before walking forwards - especially when making a jump.
When you get up the first web on the lantern - you have to jump across to the second web. Don't bother trying to land on the ceiling-bone-claw thing. You can jump up onto the chain then safely from on top of the box with no risk to fall down. Line up carefully, but it's pretty forgiving on the chain just remember to "aim" with your mouse ideally, instead of WASD etc.
Try right-clicking the spiders! Kapow!