I spent way too many hours...
The game by design is supposed to be long and challenging, but if the game is getting boring and repetitive, perhaps there's something the forum can help you work out?
I just completed a play through where I didn't run a dungeon twice, didn't grind at all and was able to make it through the Arc on Hard with solid equipment and a solid build. So if you're finding a need to grind too much, you might need to adjust your build to be a better suited for the game.
I might suggest you try a Cleric. Rogues are a bit more a challenge, being squishy and all.
Also, the Casual setting is a fairly easy setting, but it doesn't, and isn't supposed, to make the game a breeze.
Thank you for your feedback.