I've only run into minor bugs that had work-arounds that didn't hinder my progress in the game. The companion AI can seem a bit wonky. But overall, I have no problems with the game and am enjoying it thus far.
For what its worth, as far as difficulty, I think that as long as you choose a setting that fits, its fine - make sure the settings don't downscale difficulty for your level. Some of the "Blessings" in the game don't do much to change the difficulty - rather they help you get started more quickly (such as starting money). But if you are looking for difficulty, prob best to avoid using that stuff.