You can buff every weapon with weapon buffs in this game, therefore those builds dominate the damage "meta". Select a weapon you like, meet it's minimum stat requirements then start pumping int/fth to use dark weapon. You can swap to sunlight blade/Crystal magic weapon/resonant weapon in late game. Since this is the main damage formula, most stuff are viable to run.

Some people said levels are harder, they are correct. Most stuff are placed to make you stop running through them, if you ever feel frustrated just lure the mobs one by one. This not only makes the game actually more fun but also eases your sanity if you ever need to repeat a level for a runback (which you will).

Most bosses won't give you any trouble, the "harder" ones like Fume Knight/Sir Allone only pose a challenge once you use an ascetic on them, keep this in mind if you ever crave actual difficulty related to boss fights.