Mighty Bend is a shortbow skill that hits fairly hard. Spamming the Fivefold Arrow technique is also pretty effective. If you want really strong archery skills you should use a ranger, and if you want weird magic homing archery skills use the magic archer. They each use different types of bows but they’re all dagger classes.
Large monsters have weak points where they take more damage, and if you knock them down they take even more damage while they’re prone. Protip: cut off the snake head on a chimera first, it’s a guaranteed knockdown. And if you encounter a cyclops with a helmet on, uhh, make him scratch his back 
I found the items overwhelming too at first but you can ignore most stuff that’s not obvious healing items. Don’t fuck around with the million different specific ailment cures imo.
There are really only a handful of combinations worth remembering too. In fact, here are all of them:
greenwarish + wormwood sap = potent greenwarish
potent greenwarish + curious wine = matured greenwarish
sap and wine are dropped by goblins and hobgoblins, respectively
sour meat (any type) + foreign knife, or some kind of rock/ore = backfat oil, gross but strong stamina regen item
moldy grandgrapes + water = red wine
moldy apple + water = red wine
good single person healing items
harspud sauce + large nuts (nice) = balmy perfume
good group healing item
You can also just fill a hundred glass bottles at a healing spring if you’re patient lol