The “holy” element is extraordinarily powerful against most foes, so your weapon choices are effectively limited.

At my first playthough, I was so tired of using Lightning all the time. It's such an obnoxious spell (thanks to its sound) but it's very efficient because Light = Good.

It's really sad that all the dark weapons are just useless. Many of them look so badass!

It’s also quite easy on default settings, while the difficulty slider seems to do nothing but inflate or deflate monster HP and damage.

Yep. Difficulty slider only changes enemies' damage, up to 500% of the initial value. I always keep it at ~300% because otherwise enemies deal such a negligible damage. But it won't make the game hard because all you need to heal up to full health is to just press one button.